This document summarizes a research paper that presents a new microfluidic origami device for point-of-care nucleic acid extraction from raw viscous samples. The low-cost paper-based device uses folding to sequence complex processing steps and does not require external power. It was able to extract bacterial DNA from a pig mucin sample spiked with E. coli. The fabrication of the device can be translated to high-volume production without need for specialized facilities. The device has potential for molecular diagnosis in resource-limited settings.
This document summarizes a microfluidic origami device for extracting nucleic acids from viscous samples at the point-of-care. Key points:
- The device uses an origami-like folding technique to sequence chemical and physical processing steps, substituting capillary flow for pumps and folding/unfolding for valves.
- It demonstrates room-temperature lysis and DNA extraction from E. coli-spiked pig mucin (simulating sputum) without external power.
- Fabrication takes less than 30 minutes using inexpensive, commercially available materials and a laser cutter. The simple design could enable production and use in resource-limited settings.
A dry process for production of microfluidic devices based on the lamination ...Veluri Vijay Chowdary
This document describes a new microfabrication process for producing microfluidic devices using a laser printer and lamination of polyester films. The process involves printing toner onto polyester films to define microchannel patterns. The printed films are then laminated together, with the toner binding the films and leaving blank regions that become channels. This creates software-defined channels approximately 6 μm deep from a single printed layer, or twice as deep from laminating two printed layers. The resulting devices were tested and shown to have some limitations but provide an attractive low-cost option for microfluidics fabrication compared to more expensive methods.
The document summarizes a study that imaged biological samples using atomic force microscopy (AFM) in dry and liquid conditions. The objectives were to image metaphase chromosomes from normal male lymphocytes and cervical tumor cells under different AFM modes and probe types, and to evaluate the imaging effects. The results showed that while contact mode in liquid increased resolution, high resolution was also achieved using intermittent contact mode in dry conditions with a high stiffness probe. Repeated height measurements showed nominal statistical differences, indicating no apparent sample damage from this method. The study demonstrated the potential of AFM for biological micro- and nano-materials characterization.
This document discusses microfluidics for cell culture applications. It begins with an introduction to microfluidics, describing it as the science of manipulating small volumes of fluids using micrometer-sized channels. Next, it covers common microfabrication techniques like photolithography and soft lithography to produce microfluidic devices. It then outlines several applications of microfluidics for cell culture, such as creating cell-on-a-chip systems that can mimic in vivo environments and enable high-throughput screening. Specific case studies are presented, including co-culturing multiple cell types and integrating cell culture with lysis on a single chip. Finally, the document concludes that microfluidic platforms show promise for advanced cell biology studies due to
This document summarizes a lecture on microfluidics and their applications including lab-on-a-chip devices. Key topics discussed include microfluidic applications in areas like blood analysis, biochemical detection, chemical synthesis, and DNA sequencing. Common microfluidic materials like silicon, glass, and polymers are also summarized. Fabrication techniques for polymers include casting, hot embossing, and injection molding. Lab-on-a-chip offers advantages of low cost, small sample/reagent sizes, and minimized harmful byproducts compared to conventional laboratories.
RECOGNITION OF CDNA MICROARRAY IMAGE USING FEEDFORWARD ARTIFICIAL NEURAL NETWORKijaia
The complementary DNA (cDNA) sequence considered the magic biometric technique for personal identification. Microarray image processing used for the concurrent genes identification. In this paper, we present a new method for cDNA recognition based on the artificial neural network (ANN). We have segmented the location of the spots in a cDNA microarray. Thus, a precise localization and segmenting of a spot are essential to obtain a more exact intensity measurement, leading to a more accurate gene expression measurement. The segmented cDNA microarray image resized and used as an input for the
proposed artificial neural network. For matching and recognition, we have trained the artificial neural
network. Recognition results are given for the galleries of cDNA sequences . The numerical results show
that, the proposed matching technique is an effective in the cDNA sequences process. The experimental
results of our matching approach using different databases shows that, the proposed technique is an effective matching performance.
Nanomaterials are materials synthesized at the nanoscale between 1-100nm. Their properties can differ greatly from their larger counterparts. For example, a gold coin is soft and yellow at normal scale but becomes hard and red at the nanoscale. Nanomaterials have many applications including in medicine for targeted drug delivery, in diagnostics like cancer detection, and in cosmetics like sunscreens with efficient UV protection. They can cross cell membranes and offer localized targeted delivery of drugs while maintaining drug solubility.
This document summarizes a microfluidic origami device for extracting nucleic acids from viscous samples at the point-of-care. Key points:
- The device uses an origami-like folding technique to sequence chemical and physical processing steps, substituting capillary flow for pumps and folding/unfolding for valves.
- It demonstrates room-temperature lysis and DNA extraction from E. coli-spiked pig mucin (simulating sputum) without external power.
- Fabrication takes less than 30 minutes using inexpensive, commercially available materials and a laser cutter. The simple design could enable production and use in resource-limited settings.
A dry process for production of microfluidic devices based on the lamination ...Veluri Vijay Chowdary
This document describes a new microfabrication process for producing microfluidic devices using a laser printer and lamination of polyester films. The process involves printing toner onto polyester films to define microchannel patterns. The printed films are then laminated together, with the toner binding the films and leaving blank regions that become channels. This creates software-defined channels approximately 6 μm deep from a single printed layer, or twice as deep from laminating two printed layers. The resulting devices were tested and shown to have some limitations but provide an attractive low-cost option for microfluidics fabrication compared to more expensive methods.
The document summarizes a study that imaged biological samples using atomic force microscopy (AFM) in dry and liquid conditions. The objectives were to image metaphase chromosomes from normal male lymphocytes and cervical tumor cells under different AFM modes and probe types, and to evaluate the imaging effects. The results showed that while contact mode in liquid increased resolution, high resolution was also achieved using intermittent contact mode in dry conditions with a high stiffness probe. Repeated height measurements showed nominal statistical differences, indicating no apparent sample damage from this method. The study demonstrated the potential of AFM for biological micro- and nano-materials characterization.
This document discusses microfluidics for cell culture applications. It begins with an introduction to microfluidics, describing it as the science of manipulating small volumes of fluids using micrometer-sized channels. Next, it covers common microfabrication techniques like photolithography and soft lithography to produce microfluidic devices. It then outlines several applications of microfluidics for cell culture, such as creating cell-on-a-chip systems that can mimic in vivo environments and enable high-throughput screening. Specific case studies are presented, including co-culturing multiple cell types and integrating cell culture with lysis on a single chip. Finally, the document concludes that microfluidic platforms show promise for advanced cell biology studies due to
This document summarizes a lecture on microfluidics and their applications including lab-on-a-chip devices. Key topics discussed include microfluidic applications in areas like blood analysis, biochemical detection, chemical synthesis, and DNA sequencing. Common microfluidic materials like silicon, glass, and polymers are also summarized. Fabrication techniques for polymers include casting, hot embossing, and injection molding. Lab-on-a-chip offers advantages of low cost, small sample/reagent sizes, and minimized harmful byproducts compared to conventional laboratories.
RECOGNITION OF CDNA MICROARRAY IMAGE USING FEEDFORWARD ARTIFICIAL NEURAL NETWORKijaia
The complementary DNA (cDNA) sequence considered the magic biometric technique for personal identification. Microarray image processing used for the concurrent genes identification. In this paper, we present a new method for cDNA recognition based on the artificial neural network (ANN). We have segmented the location of the spots in a cDNA microarray. Thus, a precise localization and segmenting of a spot are essential to obtain a more exact intensity measurement, leading to a more accurate gene expression measurement. The segmented cDNA microarray image resized and used as an input for the
proposed artificial neural network. For matching and recognition, we have trained the artificial neural
network. Recognition results are given for the galleries of cDNA sequences . The numerical results show
that, the proposed matching technique is an effective in the cDNA sequences process. The experimental
results of our matching approach using different databases shows that, the proposed technique is an effective matching performance.
Nanomaterials are materials synthesized at the nanoscale between 1-100nm. Their properties can differ greatly from their larger counterparts. For example, a gold coin is soft and yellow at normal scale but becomes hard and red at the nanoscale. Nanomaterials have many applications including in medicine for targeted drug delivery, in diagnostics like cancer detection, and in cosmetics like sunscreens with efficient UV protection. They can cross cell membranes and offer localized targeted delivery of drugs while maintaining drug solubility.
El documento trata sobre el manejo y control de inventarios en las empresas. Explica que los inventarios tienen como propósito proveer materiales necesarios a la empresa para su funcionamiento regular y enfrentar la demanda. También describe las cuentas relacionadas con los inventarios como compras, ventas, inventario inicial y final. Finalmente, destaca la importancia de la administración de inventarios para minimizar costos e invertir adecuadamente en inventarios para satisfacer la demanda.
Este documento habla sobre el valor del respeto. Define el respeto como aceptar y comprender a los demás tal como son, incluyendo sus formas de pensar aunque sean diferentes a las nuestras. Explica que el respeto se vive mostrando aprecio por los derechos y dignidad de las personas, así como por el entorno natural. También enumera diversas formas de mostrar respeto hacia uno mismo, los demás, los valores, la patria y la naturaleza. Finalmente, ofrece ejemplos de cómo nos sentimos respetados o irrespetados.
El documento describe a la familia del autor, incluyendo a su abuela de 76 años que le gusta el teatro asiático pero no los dulces, su tranquilo abuelo que prefiere el pescado sobre la carne, su padre tranquilo Liu Guo que también le gusta el pescado pero no los dulces, y su madre Yin Fang que le gusta leer pero no el cerdo.
Conscius instructor disciplinado e incondicionalGiannis Morales
El documento describe las ventajas y desventajas del uso de plataformas de aprendizaje como Moodle. Ofrece herramientas para organizar cursos y comunicarse con estudiantes, pero requiere que los docentes y estudiantes aprendan a usar todas sus funciones para aprovechar su potencial. También puede mejorarse la velocidad y facilidad de uso.
El cuento "Francisca y la Muerte" narra la historia de una anciana llamada Francisca que siempre está ocupada realizando tareas y ayudando a otros. La Muerte intenta encontrarla varias veces para llevársela, pero nunca puede porque Francisca siempre está activa y ocupada. El cuento demuestra el valor de la responsabilidad, ya que a pesar de su edad avanzada, Francisca sigue comprometida con sus deberes diarios.
Este documento describe los pasos para reinstalar el software y controladores en una computadora. Explica que el software proporciona herramientas para que los usuarios realicen diferentes tareas. Luego detalla los pasos para insertar el disco de instalación, ir al Panel de control, agregar o quitar programas, seleccionar agregar desde un disco o CD, y seguir las instrucciones del asistente de instalación.
El documento discute el proceso complejo de elaborar una hamburguesa y cómo los factores sociales moldean el pensamiento y comportamiento humanos. Explica brevemente tres teorías sociológicas sobre el cambio social: 1) El funcionalismo de Durkheim ve a la sociedad como un organismo donde las partes trabajan juntas por el bien común. 2) El conflicto de Marx argumenta que el comportamiento social resulta de la tensión entre grupos de poder. 3) El interaccionismo de Goffman compara la sociedad a una obra de teatro donde las personas actú
El documento trata sobre la psicología del arte. Define el arte como algo que une según su etimología. Explica que la psicología del arte estudia la relación entre el arte y las psicopatologías. Además, señala que el arte terapia utiliza la expresión artística para resolver conflictos de forma individual o grupal y que niega la idea del artista genial alejado de la normalidad. Por último, compara el juego con el arte y señala que ambos permiten apoyar la imaginación en objetos reales aunque la creativ
La honestidad consiste en tomar acciones que construyan una sociedad ideal a largo plazo, no solo buscando el propio interés a corto plazo. La honestidad implica ponerse en el lugar de otros y elegir acciones que no dañen el honor de la familia, ya sea en el presente o en el futuro. Reconocer las propias motivaciones puede mejorar los actos buenos o malos.
La Unión Europea ha acordado un embargo petrolero contra Rusia en respuesta a la invasión de Ucrania. El embargo prohibirá la mayoría de las importaciones de petróleo ruso a la UE y se implementará de manera gradual durante los próximos seis meses. El embargo forma parte de un sexto paquete de sanciones de la UE contra Rusia destinado a aumentar la presión económica sobre el gobierno de Putin.
Este documento proporciona una introducción a los diferentes grupos de animales, comenzando con las esponjas, celentéreos y equinodermos, seguidos de gusanos y moluscos, artrópodos, vertebrados como peces, anfibios, reptiles, aves y mamíferos. Explica las características distintivas de cada grupo y algunos ejemplos representativos.
Este documento presenta una lista de 4 integrantes y describe los derechos morales y patrimoniales del autor sobre su obra. Los derechos morales incluyen el derecho a la paternidad, a oponerse a modificaciones y a dejar la obra inédita. Los derechos patrimoniales permiten al autor disponer libremente de su obra y obtener un beneficio económico. El documento también menciona convenios y leyes internacionales relacionadas con los derechos de autor.
La música ha evolucionado a lo largo de la historia. El hombre primitivo usaba la danza y ceremonias religiosas acompañadas de sonidos. Más tarde, Guido d'Arezzo creó el pentagrama musical en el siglo X. Instrumentos como el piano, el violín y la flauta fueron desarrollados a través de los siglos. La clasificación de instrumentos se basa en el material que produce el sonido, como aire, membranas, cuerdas u otros materiales.
El documento presenta una lista de los principales destinos turísticos en México, incluyendo Puerto Vallarta en Jalisco, conocida por sus playas y belleza natural; Isla Mujeres en Quintana Roo, una isla encantadora con actividades acuáticas; y Oaxaca, un estado con una rica cultura y muchos sitios históricos. También menciona Mazatlán en Sinaloa, famoso por sus playas y carnaval, y Cabo San Lucas en Baja California, un puerto para cruceros y observación de ballenas conocido por su clima
Asia es el continente más grande del mundo, abarcando 44.4 millones de km2 entre los trópicos y el círculo polar ártico. El Oriente Próximo, la región de Asia más cercana al Mediterráneo, tiene una rica tradición musical que va más allá de acompañar rituales, buscando armonizar el universo y las fuerzas internas individuales, requiriendo de un estado de ánimo espiritual para ser plenamente apreciada.
Google Maps es un servicio gratuito de Google que ofrece imágenes de mapas interactivos del mundo entero, incluyendo fotos satelitales y callejeado Street View. Sus características incluyen la capacidad de acercar y alejar el mapa, ubicar taxis o transporte público en tiempo real, e imágenes satelitales de alta resolución disponibles para la mayoría de Norteamérica.
Satish Kadiyala is an Oracle database professional with over 5 years of experience in areas like analysis, design, development, testing, and maintenance of applications using Oracle PL/SQL. He has extensive skills in Oracle database administration, performance tuning, and database migration. His work experience includes projects involving database migration from Oracle to PostgreSQL for Schlumberger and developing a payment gateway system for CIMB Malaysia.
China Medical University Student ePaper2Isabelle Chiu
Microarray and bio-chips provide a new technology for analyzing samples in an instant, automatic, and high-efficiency way. Microarray biochips can be divided into DNA chips and protein chips. DNA chips use nucleic acids as probes to examine thousands of genes simultaneously, while protein chips use proteins, antibodies, or microorganisms as probes to detect factors like hormones. Microarray biochips allow many samples, reagents, and biological materials to react on a small, miniaturized device, generating data immediately after quantitative analysis. This technology is being developed for uses in medical diagnostics and drug development.
Launching digital biology, 12 May 2015, Bremenbioflux
Intro. It is not a secret that in biology laboratories hours of manual work are considered a compulsory part of the experiment. During a day of work, lab researchers have to pipette the right amounts of fluids in tubes, carry them from one machine to another, program and handle each machine individually, label and document carefully each step and then convert the results to data and analyse it. For a simple routine experiment, each of the mentioned tasks is performed at least 10 times/day. Past decade, a big effort has been done to produce machines (e.g., pipetting robots) that would automate some of the tasks in the lab. However, these machines were developed under the industrial mindset to maximize the throughput of a single task. Thus, these machines are of large size, task-specific, difficult to use (they usually come with dedicated drivers and software) and most importantly, extremely expensive. A solution is the use of digital microfluidics to enable the advance from automated biology to digital biology. In my vision, a digital lab should be:
• fully integrated, running all the tasks on the same machine
• easy to use, with a web-based software for biological design of new experiments and hardware control
• general-purpose, allowing easy reconfiguration and design of new experiments
• cheap, offering open-source and do-it-yourself assembly kits
Talk. In the talk, I will present an overview of the road to digital biology, covering all the main aspects, from computer-aided design to hardware production and biological applications.
Hands on. Also, prepare for some real engineering action :). I will execute live a biochemical application (enzymatic reaction of β-galactosidase with Xgal) on my homemade digital biochip. We will then discuss the current challenges in the development process and everyone will get a chance to play with the device. And of course, I will happily consider any engineering advice or idea you have :).
Digital microfluidic biochips manipulate discrete droplets of fluid across an array of electrodes for applications in biomedical analysis. They offer advantages over continuous flow chips by allowing droplets to be transported independently without pumps or valves. Droplets containing samples or reagents are sandwiched between insulating and hydrophobic coated glass plates, with one plate patterned with electrodes. Applying voltage gradients moves droplets from one electrode to the next. Potential applications include diagnostic tests, chemical detection, and tissue engineering due to their small size, low cost, and ability to precisely control small fluid volumes.
El documento trata sobre el manejo y control de inventarios en las empresas. Explica que los inventarios tienen como propósito proveer materiales necesarios a la empresa para su funcionamiento regular y enfrentar la demanda. También describe las cuentas relacionadas con los inventarios como compras, ventas, inventario inicial y final. Finalmente, destaca la importancia de la administración de inventarios para minimizar costos e invertir adecuadamente en inventarios para satisfacer la demanda.
Este documento habla sobre el valor del respeto. Define el respeto como aceptar y comprender a los demás tal como son, incluyendo sus formas de pensar aunque sean diferentes a las nuestras. Explica que el respeto se vive mostrando aprecio por los derechos y dignidad de las personas, así como por el entorno natural. También enumera diversas formas de mostrar respeto hacia uno mismo, los demás, los valores, la patria y la naturaleza. Finalmente, ofrece ejemplos de cómo nos sentimos respetados o irrespetados.
El documento describe a la familia del autor, incluyendo a su abuela de 76 años que le gusta el teatro asiático pero no los dulces, su tranquilo abuelo que prefiere el pescado sobre la carne, su padre tranquilo Liu Guo que también le gusta el pescado pero no los dulces, y su madre Yin Fang que le gusta leer pero no el cerdo.
Conscius instructor disciplinado e incondicionalGiannis Morales
El documento describe las ventajas y desventajas del uso de plataformas de aprendizaje como Moodle. Ofrece herramientas para organizar cursos y comunicarse con estudiantes, pero requiere que los docentes y estudiantes aprendan a usar todas sus funciones para aprovechar su potencial. También puede mejorarse la velocidad y facilidad de uso.
El cuento "Francisca y la Muerte" narra la historia de una anciana llamada Francisca que siempre está ocupada realizando tareas y ayudando a otros. La Muerte intenta encontrarla varias veces para llevársela, pero nunca puede porque Francisca siempre está activa y ocupada. El cuento demuestra el valor de la responsabilidad, ya que a pesar de su edad avanzada, Francisca sigue comprometida con sus deberes diarios.
Este documento describe los pasos para reinstalar el software y controladores en una computadora. Explica que el software proporciona herramientas para que los usuarios realicen diferentes tareas. Luego detalla los pasos para insertar el disco de instalación, ir al Panel de control, agregar o quitar programas, seleccionar agregar desde un disco o CD, y seguir las instrucciones del asistente de instalación.
El documento discute el proceso complejo de elaborar una hamburguesa y cómo los factores sociales moldean el pensamiento y comportamiento humanos. Explica brevemente tres teorías sociológicas sobre el cambio social: 1) El funcionalismo de Durkheim ve a la sociedad como un organismo donde las partes trabajan juntas por el bien común. 2) El conflicto de Marx argumenta que el comportamiento social resulta de la tensión entre grupos de poder. 3) El interaccionismo de Goffman compara la sociedad a una obra de teatro donde las personas actú
El documento trata sobre la psicología del arte. Define el arte como algo que une según su etimología. Explica que la psicología del arte estudia la relación entre el arte y las psicopatologías. Además, señala que el arte terapia utiliza la expresión artística para resolver conflictos de forma individual o grupal y que niega la idea del artista genial alejado de la normalidad. Por último, compara el juego con el arte y señala que ambos permiten apoyar la imaginación en objetos reales aunque la creativ
La honestidad consiste en tomar acciones que construyan una sociedad ideal a largo plazo, no solo buscando el propio interés a corto plazo. La honestidad implica ponerse en el lugar de otros y elegir acciones que no dañen el honor de la familia, ya sea en el presente o en el futuro. Reconocer las propias motivaciones puede mejorar los actos buenos o malos.
La Unión Europea ha acordado un embargo petrolero contra Rusia en respuesta a la invasión de Ucrania. El embargo prohibirá la mayoría de las importaciones de petróleo ruso a la UE y se implementará de manera gradual durante los próximos seis meses. El embargo forma parte de un sexto paquete de sanciones de la UE contra Rusia destinado a aumentar la presión económica sobre el gobierno de Putin.
Este documento proporciona una introducción a los diferentes grupos de animales, comenzando con las esponjas, celentéreos y equinodermos, seguidos de gusanos y moluscos, artrópodos, vertebrados como peces, anfibios, reptiles, aves y mamíferos. Explica las características distintivas de cada grupo y algunos ejemplos representativos.
Este documento presenta una lista de 4 integrantes y describe los derechos morales y patrimoniales del autor sobre su obra. Los derechos morales incluyen el derecho a la paternidad, a oponerse a modificaciones y a dejar la obra inédita. Los derechos patrimoniales permiten al autor disponer libremente de su obra y obtener un beneficio económico. El documento también menciona convenios y leyes internacionales relacionadas con los derechos de autor.
La música ha evolucionado a lo largo de la historia. El hombre primitivo usaba la danza y ceremonias religiosas acompañadas de sonidos. Más tarde, Guido d'Arezzo creó el pentagrama musical en el siglo X. Instrumentos como el piano, el violín y la flauta fueron desarrollados a través de los siglos. La clasificación de instrumentos se basa en el material que produce el sonido, como aire, membranas, cuerdas u otros materiales.
El documento presenta una lista de los principales destinos turísticos en México, incluyendo Puerto Vallarta en Jalisco, conocida por sus playas y belleza natural; Isla Mujeres en Quintana Roo, una isla encantadora con actividades acuáticas; y Oaxaca, un estado con una rica cultura y muchos sitios históricos. También menciona Mazatlán en Sinaloa, famoso por sus playas y carnaval, y Cabo San Lucas en Baja California, un puerto para cruceros y observación de ballenas conocido por su clima
Asia es el continente más grande del mundo, abarcando 44.4 millones de km2 entre los trópicos y el círculo polar ártico. El Oriente Próximo, la región de Asia más cercana al Mediterráneo, tiene una rica tradición musical que va más allá de acompañar rituales, buscando armonizar el universo y las fuerzas internas individuales, requiriendo de un estado de ánimo espiritual para ser plenamente apreciada.
Google Maps es un servicio gratuito de Google que ofrece imágenes de mapas interactivos del mundo entero, incluyendo fotos satelitales y callejeado Street View. Sus características incluyen la capacidad de acercar y alejar el mapa, ubicar taxis o transporte público en tiempo real, e imágenes satelitales de alta resolución disponibles para la mayoría de Norteamérica.
Satish Kadiyala is an Oracle database professional with over 5 years of experience in areas like analysis, design, development, testing, and maintenance of applications using Oracle PL/SQL. He has extensive skills in Oracle database administration, performance tuning, and database migration. His work experience includes projects involving database migration from Oracle to PostgreSQL for Schlumberger and developing a payment gateway system for CIMB Malaysia.
China Medical University Student ePaper2Isabelle Chiu
Microarray and bio-chips provide a new technology for analyzing samples in an instant, automatic, and high-efficiency way. Microarray biochips can be divided into DNA chips and protein chips. DNA chips use nucleic acids as probes to examine thousands of genes simultaneously, while protein chips use proteins, antibodies, or microorganisms as probes to detect factors like hormones. Microarray biochips allow many samples, reagents, and biological materials to react on a small, miniaturized device, generating data immediately after quantitative analysis. This technology is being developed for uses in medical diagnostics and drug development.
Launching digital biology, 12 May 2015, Bremenbioflux
Intro. It is not a secret that in biology laboratories hours of manual work are considered a compulsory part of the experiment. During a day of work, lab researchers have to pipette the right amounts of fluids in tubes, carry them from one machine to another, program and handle each machine individually, label and document carefully each step and then convert the results to data and analyse it. For a simple routine experiment, each of the mentioned tasks is performed at least 10 times/day. Past decade, a big effort has been done to produce machines (e.g., pipetting robots) that would automate some of the tasks in the lab. However, these machines were developed under the industrial mindset to maximize the throughput of a single task. Thus, these machines are of large size, task-specific, difficult to use (they usually come with dedicated drivers and software) and most importantly, extremely expensive. A solution is the use of digital microfluidics to enable the advance from automated biology to digital biology. In my vision, a digital lab should be:
• fully integrated, running all the tasks on the same machine
• easy to use, with a web-based software for biological design of new experiments and hardware control
• general-purpose, allowing easy reconfiguration and design of new experiments
• cheap, offering open-source and do-it-yourself assembly kits
Talk. In the talk, I will present an overview of the road to digital biology, covering all the main aspects, from computer-aided design to hardware production and biological applications.
Hands on. Also, prepare for some real engineering action :). I will execute live a biochemical application (enzymatic reaction of β-galactosidase with Xgal) on my homemade digital biochip. We will then discuss the current challenges in the development process and everyone will get a chance to play with the device. And of course, I will happily consider any engineering advice or idea you have :).
Digital microfluidic biochips manipulate discrete droplets of fluid across an array of electrodes for applications in biomedical analysis. They offer advantages over continuous flow chips by allowing droplets to be transported independently without pumps or valves. Droplets containing samples or reagents are sandwiched between insulating and hydrophobic coated glass plates, with one plate patterned with electrodes. Applying voltage gradients moves droplets from one electrode to the next. Potential applications include diagnostic tests, chemical detection, and tissue engineering due to their small size, low cost, and ability to precisely control small fluid volumes.
Sk microfluidics and lab on-a-chip-ch5stanislas547
This document discusses Lab-on-a-Chip (LOC) technology and its applications in biomedical fields. LOC systems integrate full laboratory functions onto a single microchip to handle extremely small fluid volumes. Key points:
- LOCs deal with fluid transport and analysis on the microscale and are a type of microfluidic device. They can perform complex analyses like DNA separation and detection.
- LOC research grew in the 1990s as groups developed micropumps and sensors to integrate fluid processing. Genomics and military applications further drove research.
- LOCs have advantages like low sample/reagent use, fast analysis, compact size, and potential for point-of-care medical diagnostics. Examples include
This document describes a microfluidic chip system that is used to programmably generate DNA libraries at the nanoliter scale. The chip allows for on-demand generation and mixing of nanoliter droplets from multiple DNA input solutions. Droplets containing DNA assemblies are exported from the chip to individual wells of a microwell plate, creating a physically separated DNA library. The researchers demonstrate the controlled combination of DNA fragments using the chip system, verified through downstream analysis methods such as PCR, gel electrophoresis, and DNA sequencing.
Biochips are small devices made from materials like silicon and plastic that can analyze thousands of biological elements simultaneously. They contain arrays of biosensors and can perform many reactions quickly. Key applications of biochips include disease diagnosis, drug development, and analyzing gene expression. The document discusses the components of biochips like transponders and readers. It also describes different types of biochips such as DNA microarrays, protein microarrays, and microfluidic chips. Finally, potential medical uses of biochips are presented, including sensors for glucose levels, oxygen levels, and blood pressure.
In this paper, we explore the use of microfluidic paper-based analytical devices (PADs) to study the behavior of Caenorhabditis elegans. We show how these devices can be fabricated on paper and plastic substrates, as well as how to load, visualize, and transfer single and multiple nematodes. We also demonstrate the use of anthelmintic drug, levamisole, to perform chemical testing on C. elegans. Furthermore, we provide a custom program that is able to recognize individual worms on the PADs in real-time and extract their locomotion parameters. This combination of PADs and the nematode tracking program creates a low-cost, easy-to-fabricate imaging and screening assay that is superior to standard agarose plates or polymeric microfluidic devices for non-microfluidic, nematode laboratories.
Zach Njus, Taejoon Kong, Upender Kalwa, Christopher Legner, Matthew Weinstein, Shawn Flanigan, Jenifer Saldanha, and Santosh Pandey, "Flexible and disposable paper- and plastic-based gel micropads for nematode handling, imaging, and chemical testing", APL Bioengineering 1, 016102 (2017)
https://doi.org/10.1063/1.5005829
https://aip.scitation.org/doi/10.1063/1.5005829
This document provides an overview of centrifugal microfluidic platforms and their applications. It discusses how centrifugal microfluidics has matured into a technology with commercial products, covering clinical chemistry, immunodiagnostics, and more. New fluidic functions continue to expand its capabilities. The document reviews centrifugal microfluidic unit operations and how they can be combined into process chains to automate laboratory workflows. It also analyzes how novel unit operations could enable more complex applications by storing pneumatic energy or reagents. Centrifugal microfluidics provides advantages over other microfluidic actuation methods like closed, pump-free liquid handling and scalable processed volumes.
Biochip technology allows thousands of biological tests to be performed simultaneously on a surface area smaller than a fingernail. A biochip contains miniaturized test sites arranged on a solid substrate that can analyze genes and other biomolecules quickly. It works by concentrating genetic tests on a small area so they can be analyzed by computer in a short time, making individual tests cheaper while allowing more tests to be conducted. A biochip is made up of a microchip containing identification information, an antenna coil, capacitor, and glass capsule that together allow it to transmit its ID to a scanner wirelessly.
This document discusses microscale bioprocessing, which involves producing commercially desired products at a very small scale. This speeds up product delivery, reduces costs, and increases consumer benefit. Two main formats are micro well systems and microfluidic systems. Microwell systems involve testing samples in small wells in plates, while microfluidic systems use channels to manipulate fluids in the micrometer range. These techniques are being applied to areas like bioprocess optimization, molecular biology procedures, diagnostics, drug discovery, and more. Microfluidics is revolutionizing fields and its market is projected to reach $6 billion by 2020. Future applications may involve nanofluidics which deals with even smaller nanometer scale fluids.
Automated platform for multiparameter stimulus response studies of metabolic ...Shashaanka Ashili
This document describes an automated platform for performing multiparameter stimulus-response studies on single cells and small groups of interacting cells. The platform allows for minimally invasive monitoring of cell phenotypes while applying various physiological stimuli through microfluidic systems. It features integrated fluorescent probes to monitor intracellular and extracellular physiological changes with high sensitivity. The platform consists of a confocal microscope, microfluidic cassette for single cell confinement and application of stimuli, and software/hardware for automated control and data collection. Preliminary results characterizing metabolic responses of single esophageal cells are presented.
This document discusses DNA-based bio-micro-electronic mechanical systems (Bio-MEMS). It describes how lab-on-a-chip devices can integrate sample treatment functions like separation and amplification on a single microchip. This allows miniature versions of biological processes to be created cheaply and efficiently using microfluidic channels. DNA microarrays are also discussed as a way to study protein interactions using fluorescent labeling and laser scanning of array spots. Finally, miniaturized polymerase chain reaction is presented as a key DNA detection method on these chips due to its ability to detect low pathogen concentrations with minimal reagents and short assay times.
1) The document describes a new DNA sequencing system that uses picolitre-sized reactors on a microfabricated chip to massively parallelize sequencing reactions and significantly increase throughput over previous methods.
2) Key aspects of the system include using emulsion PCR to amplify DNA fragments on beads in picolitre droplets and performing pyrosequencing reactions in the high-density array of picolitre wells on the chip.
3) The document demonstrates the capabilities of the system by sequencing the genome of Mycoplasma genitalium and assembling it de novo, achieving 96% coverage of the 580 kb genome in a single run at 99.96% accuracy.
IRJET- Nanorobots: Application in Data MiningIRJET Journal
This document discusses the potential applications of nanorobots in data mining. It begins with an introduction to the field of nanorobotics and defines nanorobots as tiny machines designed to perform tasks at the nanoscale. The document then describes the potential structure and components of nanorobots, including medicine cavities, probes, knives, chisels, microwave emitters, ultrasonic signal generators, electrodes, and lasers. Various types of nanorobots are also outlined. The document focuses on how nanorobots could be used for data mining through information processing at the nanoscale. It then lists several other potential applications of nanorobots in fields like cryonics, nanomedicine, surgery, hematology, diabetes treatment
FORMATION OF NANOPARTICLES FROM PLANT EXTRACT VIKASH RAWAT
This document is a project report submitted by Vikash Rawat for a summer research training program on the preparation of nanoparticles from plant extracts. It includes an introduction that discusses different synthesis methods for nanoparticles including top-down and bottom-up approaches. It also discusses nucleation and growth kinetics. The report contains sections on methodology, applications, and conclusions. It includes lists of tables and figures to illustrate different synthesis techniques such as physical vapor deposition, chemical vapor deposition, and biogenic synthesis using plant extracts.
Paper –based analytical devises are easy to use, portable and disposable. They can be used for many applications ranging from biomedical detection to environmental applications. This is because the promising property of paper that allows microfluidic transport of liquids makes a very good platform for detecting chemical and biochemical analytes. In order to suit the goal for detection paper can be fabricated and manipulated using different techniques
This document describes a microfluidic bioreactor system developed to provide controlled spatial and temporal concentration gradients of multiple molecular factors to 3D cultures of human pluripotent stem cells. The bioreactor contains rows of microwells connected by microchannels that generate stable concentration gradients when different factors are flowed through the lateral channels. Human embryonic and induced pluripotent stem cells were cultured as embryoid bodies in the bioreactor and exposed to gradients of mesoderm-inducing morphogens. Gene expression analysis showed the system could evaluate the initiation of mesodermal induction in a controlled manner. The bioreactor aims to provide a more in vivo-like model for studying stem cell development and differentiation.
Design of Organ-On-A-Chip - Creative Biolabs.pptxCreative-Biolabs
Creative Biolabs has developed an extensive microfluidic technology platform, offering customers one-stop services covering all aspects of microfluidic research and evaluation. This includes the design and manufacturing of organ-on-a-chip (OOC) systems, as well as personalized, customized solutions tailored to individual needs.
This slide briefly introduces our OOC design concepts. If you require further details, products, and services related to OOC, please follow us to stay updated and informed.
Flexible chip for long-term antimicrobial resistance experimentsIowa State University
By creating a low-cost, three-dimensional microfluidic platform, we have improved our ability to study bacterial cells at the single cell level. This technology allows for prolonged culturing of bacteria in a controlled environment, as well as high resolution observation and imaging of cells. We have used this platform to examine morphological changes in Escherichia coli exposed to ampicillin and to quantify the minimum inhibitory concentration of the antibiotic. Additionally, we demonstrated the potential for precise gene regulation using CRISPR interference (CRISPRi) in a concentration gradient. Ultimately, this engineering tool should be useful for uncovering new genetic factors that influence antibiotic susceptibility and evaluating the long-term effectiveness of antibiotics.
Adhesive Tape Microfluidics with an Autofocusing Module That Incorporates CRISPR Interference: Applications to Long-Term Bacterial Antibiotic Studies, Taejoon Kong, Nicholas Backes, Upender Kalwa, Christopher Legner, Gregory J. Phillips, and Santosh Pandey, ACS Sensors 2019 4 (10), 2638-2645
https://doi.org/10.1021/acssensors.9b01031
https://pubs.acs.org/doi/full/10.1021/acssensors.9b01031
This document describes a study using multiphoton microscopy (MPM) to image intrinsic fluorescence in splenic tissue from a mouse model of sickle cell disease (SCD). MPM was used to identify distinct morphological and spectral features associated with SCD, including spectrally unique iron-complex deposits. These deposits were found at higher concentrations in diseased tissue compared to healthy tissue. Identification of these biomarkers could provide insight into immune dysfunction and organ malfunction in SCD. Histological staining and white light microscopy were also used for comparison.
This document describes a study on using mid-infrared absorption spectroscopy for label-free detection of phospholipid biomarkers. Phospholipids exhibit strong absorption resonances in the mid-infrared region and are detectable using this technique. The study explores separating phospholipid biomarkers using on-chip capillary electrophoresis in a PDMS microfluidic chip, and then performing label-free detection of the separated biomarkers using mid-infrared absorption spectroscopy by interrogating the biomarkers in the microfluidic channel. Initial experiments detect a phospholipid called phosphatidic acid dissolved in a non-aqueous solvent using this approach, demonstrating the feasibility of the technique for label-free phospholipid sensing.
Optical Quilt Packaging (OQP) is a novel technique for efficient optical coupling between chips for modular mid-infrared sensors. It uses lithographically defined interdigitated copper nodules on the edges of chips to align waveguides with sub-micron accuracy. Simulations show coupling losses better than 6 dB for gaps under 4 microns. Initial OQP structures were fabricated with a 1 micron misalignment and 10 micron gap between Ge-on-Si waveguides on separate chips. Future work will measure optical losses between aligned QCL and waveguide chips coupled using OQP.
1) The document presents an experimental validation of a super-sensitive chemical imaging technique called multiphoton frequency-domain fluorescence lifetime imaging microscopy (MPM-FD-FLIM).
2) The experiments demonstrate a 2x improvement in imaging speed compared to the theoretical limit of conventional MPM-FD-FLIM. Additionally, unprecedented sensitivity is achieved over a wide range of fluorescence lifetimes.
3) These results are obtained through simple modifications to data analysis in a conventional MPM-FD-FLIM microscope based on an analytical model describing the signal-to-noise ratio of such systems. The experimental results validate this theoretical model.
1) Multi-photon microscopy was used to characterize the intrinsic fluorescence of sickle cell disease hemoglobin (HbS). HbS demonstrated broad emission around 510 nm when excited at 800 nm.
2) MPM was able to dynamically induce and image HbS gel formation through photolysis of deoxygenated HbS. Healthy hemoglobin (HbA) remained in solution and did not form fibers under the same conditions.
3) The intrinsic fluorescence of HbS fibers could enable the study of environmental factors that impact HbS polymerization and sickling of red blood cells, which is relevant for understanding sickle cell disease.
The document describes a new oxygen imaging probe consisting of a ruthenium complex encapsulated within a silica-coated Pluronic nanomicelle. The silica coating improves the biostability of the probe in biological media like PBS by a factor of 4 compared to an uncoated probe. However, the silica coating also reduces the oxygen sensitivity of the probe by a factor of 3, though the sensitivity remains comparable to other oxygen probes. Characterization of the probe's response to varying oxygen levels using Stern-Volmer analysis confirmed the probe retains sensitivity to oxygen concentrations despite the reduced sensitivity from the silica coating. The silica-coated probe shows potential for in vivo oxygen imaging applications due to its improved stability and adequate oxygen
1) The document analyzes the theoretical signal-to-noise ratio (SNR) of two-photon oxygen imaging probes based on Stern-Volmer kinetics and Poisson statistics.
2) It derives an equation for the saturation-limited SNR as a function of the probe's Stern-Volmer constant (KSV), quantum yield (η), and lifetime (τ0).
3) The analysis shows that probes with higher KSV, η and shorter τ0 will have higher SNR, and identifies an optimal KSV for physiological oxygen levels.
1) Ruthenium-poloxamer nanoprobes were prepared by encapsulating the hydrophobic ruthenium dye [Ru(dpp)3]Cl2 in poloxamer 407 surfactant micelles, providing a simple method for aqueous solubilization.
2) Two-photon microscopy of a mouse brain in vivo was performed using the probes, demonstrating excellent imaging quality and contrast of the brain vasculature down to 100 μm resolution.
3) The probes showed good two-photon excitation properties, oxygen sensitivity through lifetime measurements, and stability, indicating potential for quantitative three-dimensional oxygen concentration mapping in tissues.
Iron deposits were identified in splenic tissue from a mouse model of sickle cell disease (SCD) using label-free multi-photon microscopy (MPM). MPM detected iron-complex deposits through their intrinsic fluorescence. Spectral analysis showed deposits had similar emission to heme. Histological analysis and image segmentation found significantly higher densities of iron deposits in SCD tissue compared to wild type controls across MPM, Prussian blue staining, and H&E staining. This suggests iron deposits may be an optical biomarker for SCD and contribute to immune dysfunction in the disease.
This document summarizes a new technique called multispectral angle-resolved dark-field microscopy (MARDI) that can automatically identify bacterial species from individual bacteria on a dry slide with over 95% accuracy without staining or tagging. MARDI collects angle- and wavelength-resolved scattering spectra from individual bacteria using a custom imaging system. Principal component analysis of the scattering spectra reveals features that allow computer-based classification to identify several bacterial species with high accuracy compared to traditional microscopy methods. The technique was tested on smears containing eight bacterial species, demonstrating its potential for automated bacterial identification.
This document describes a technique called multispectral angular-resolved dark-field imaging (MARDI) that can automatically identify individual bacteria based on their unique light scattering spectra. An 87-channel microscope system was used to measure the scattering spectra of various bacteria at different angles and wavelengths. A simpler 15-channel system then demonstrated the viability of bacterial identification, accurately identifying four out of six bacterial species in tests of individual bacteria. This technique could provide a simple way to identify bacteria without the need for specialized equipment or skills.
1. The document summarizes research on novel ruthenium-complex probes for two-photon dissolved oxygen imaging.
2. The probes involve encapsulating the hydrophobic oxygen indicator [Ru(dpp)3]2+ in poloxamer nanomicelles. This preserves the oxygen sensitivity and allows for two-photon induced phosphorescence.
3. Experiments demonstrated the encapsulated probes exhibit oxygen-dependent changes in phosphorescence lifetime consistent with the Stern-Volmer relationship. They also exhibited two-photon absorption, showing potential as economical probes for quantitative two-photon oxygen imaging.
This document summarizes a study using multiphoton microscopy (MPM) to image ex vivo mouse splenic tissue samples from both healthy mice and mice with sickle cell disease (SCD). MPM was able to detect intrinsic two-photon excited fluorescence (TPEF) from endogenous fluorophores like NADH as well as morphological features. Spectral analysis found increased longer wavelength emission, associated with inflammation, in SCD tissue compared to healthy tissue. The results demonstrate MPM's potential for non-invasive monitoring of SCD progression by extracting clinically relevant information from intrinsic tissue markers.
2. A low cost point-of-care viscous sample preparation device for molecular
diagnosis in the developing world; an example of microfluidic origami†
A. V. Govindarajan, S. Ramachandran, G. D. Vigil, P. Yager and K. F. B€ohringer*
Received 11th July 2011, Accepted 21st October 2011
DOI: 10.1039/c1lc20622b
The lab-on-a-chip concept has led to several point-of-care (POC) diagnostic microfluidic platforms.
However, few of these can process raw samples for molecular diagnosis and fewer yet are suited for use
in a resource-limited setting without permanent electrical infrastructure. We present here a very low
cost paper microfluidic device for POC extraction of bacterial DNA from raw viscous samples—
a challenge for conventional microfluidic platforms. This is an example of ‘‘microfluidic origami’’ in
that the system is activated by folding; demonstrated here is room temperature cell lysis and DNA
extraction from pig mucin (simulating sputum) spiked with E. coli without the use of external power.
The microfluidic origami device features dry reagent storage and rehydration of the lysis buffer. We
demonstrate DNA extraction from samples with a bacterial load as low as 33 CFU mlÀ1
. Extraction
times, starting from the raw sample, have been optimized to about 1.5 h without the use of external
power, or to within 1 h using an oven or a heater block. The fabrication of this paper microfluidic device
can be translated into high volume production in the developing world without the need for
a semiconductor clean room or a microfabrication facility. The sample preparation can be performed
with the addition of just the sample, water, ethanol and elute buffer to the device, thus reducing
chemical hazards during transport and handling.
Introduction
The development of nucleic acid amplification tests (NAATs) has
opened the doors for highly specific molecular diagnosis and
personalized medicine. These tests are currently available in
advanced healthcare facilities and are limited in their distribution
by their cost and by the lack of point-of-care (POC) sample
preparation systems. Simple sample preparation will bring down
the cost of molecular diagnosis and make it more accessible. Our
goal is two-fold: i) to develop an extremely inexpensive, self-
contained, disposable, portable nucleic acid extraction device
and ii) to use it to demonstrate extraction of bacterial DNA from
a viscous sample matrix, which presents a challenge for
conventional microfluidic devices.
We describe here the development of a simple paper micro-
fluidic platform for sample preparation. Sample preparation is
the first step to nucleic acid-based diagnosis; our long-term goal
for the technology shown in this paper is to simplify this complex
process such that the cost of nucleic acid extraction will even-
tually be less than US$2 per patient.
Since the lab on paper review article1
published in 2008, low
cost paper diagnostics,2–13
including those based on enzyme-
linked immunosorbent assay (ELISA)2
, sequential reagent
delivery,3
multiplexed bioassays,8
and the integration of paper
microfluidics with commercial electrochemical readers14
have
been emerging for diagnostic applications in the developing
world. Such devices must be inexpensive, rugged, lightweight,
and independent of supporting infrastructure.10
Despite
advances in conventional and paper microfluidic technology, the
lack of development in sample preparation systems has led to
there being few lab-on-chip15–19
/lab-on-paper5,6
systems that can
extract nucleic acids (NA) from raw samples.
We describe our sample preparation platform as an example of
‘‘microfluidic origami’’ because it is fabricated from a stack of flat
polymer sheets and paper, and is activated by folding, Demon-
strated here is room-temperature cell lysis and DNA extraction
from pig mucin (simulating sputum) spiked with E. coli without
the use of external power.
A preliminary version of this platform without dry reagent
storage was presented at the IEEE International Conference on
Microelectromechanical Systems.20
This paper introduces an
integrated POC platform that can be operated with the addition
of just water, ethanol and elute buffer to the device. This low cost
origami-based sample preparation method in combination with
an existing or to be developed portable NAAT based system
should yield a raw sample-to-result molecular diagnosis in less
than 2 h. As a stand-alone device, our approach enables storage
of point-of-care extracted DNA for transport at room temper-
ature to more centralized diagnostic facilities. This will be
University of Washington, Electrical Engineering, Campus Box 352500,
Seattle, WA, USA 98195. E-mail: karlb@u.washington.edu; Fax: +1-
206-543-3842; Tel: +1-206-221-5177
† Electronic supplementary information (ESI) available. See DOI:
10.1039/c1lc20622b
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3. especially useful in the absence of reliable cold shipment or
a portable NA amplification system—a typical situation in rural
areas of the developing world. This work is the first step towards
providing a low cost, low power alternative to a fully automated
and portable sample preparation module of an integrated system
like the Cepheid GeneXpert.21
The GeneXpert uses self-con-
tained, single use, biosafe, microfluidic cartridges that feature
ultrasonic lysis of the filter-captured organisms to release
DNA.22
The core idea of this microfluidic origami sample preparation
device (Fig. 1) is sequencing complex chemical and physical
processing steps through sequential folding of pieces of a flat
substrate. This folding sequence puts different paper fluidic
circuits in contact with new solvent and reagent sample pads,
substituting capillary flow for pumps, and folding and unfolding
for valve activation. This microfluidic origami device separates
the process into steps on several layers (L0–L4) that fold above
or below the central layer L0, which consists of the core
elements—the DNA binding filter and a dry lysis buffer storage
pad. The device in its present form is disposable and is designed
as a single use, inexpensive device that can process one sample at
a time.
Materials
Sample matrix and bacteria
Commercial mucin (M1778 mucin from porcine stomach, type
III, bound sialic acid 0.5–1.5%, partially purified powder from
Sigma-Aldrich) was used to simulate sputum. A sample of 20%
(w/v) pig mucin in nuclease-free water resembled human sputum
in viscosity, stickiness and color. However, the mucin can
contain traces of E. coli. To ensure that the extracted and
amplified DNA was from the bacterial cell lysis rather than the
sample matrix, a transformed E. coli strain, XL1 blue trans-
formed with plasmid DNA H127KSApuc18, was used to spike
the mucin in our experiments.
Device fabrication and assembly
A single device fabrication (Fig. 2) took less than 30 min. The
fabrication consists of stacking layers of paper, Mylar (Fraylock,
Inc., San Carlos, CA, USA) and repositionable adhesive, fol-
lowed by laser cutting. The approach of making both through
Fig. 1 Microfluidic origami device for point-of-care nucleic acid
extraction. A. Front side, B. Backside, 1. DNA filter, 2. Waste absorption
pad with Mylar backing, 3. Sample loading cup, 4. Lysis/wash buffer
storage and rehydration pad. 5. Buffer transport channel. 6. Contact
stack. L1.L4: Layers that fold above and below layer L0.
Figure reprinted from Govindarajan et al.2
Fig. 2 Microfluidic origami NA extraction device fabrication. A. Stack
layering, B. Stack through cuts, C. Stack partial cuts, D. Peeling between
repositionable window decal and 4 mil Mylar layer to define paper fluidic
channels on a non-wicking substrate. The repositionable adhesive film
served both as a structural and sacrificial layer. After laser cutting with
varying power, the repositionable film was peeled away from the
substrate, leaving behind the entire stack in the lower power cut areas, E.
Front side assembly of pre-cut parts (with laser cut 3M Scotch mounting
tape, serving as spacer), F. Assembling pre-cut parts on backside. Laser
cut 3M Scotch mounting tape and Millipore cellulose paper was used to
form the sample-loading cup to accommodate larger sample volumes.
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4. cuts and partial cuts (by varying the laser power) in combination
with peeling of a repositionable adhesive layer presents a low cost
alternative to the FLASH method11
for defining paper fluidic
channels on a non-wicking substrate. The stacking of layers of
the origami from top to bottom was done by hand using a rolling
pin to press the sheets together. The origami stack layers from
top to bottom comprised of cellulose paper (Millipore, Billerica,
MA, USA), 0.5 mil Mylar with double-side adhesive, reposi-
tionable adhesive layer (RoyalBrites window decals, Norwalk
CT), 4 mil Mylar with single side adhesive and card paper to
enable bidirectional folding.
The entire stack was placed in a laser cutting machine (M-360
laser engraving and cutting system, Universal Laser Systems Inc,
Scottsdale AZ, with a 35 watt CO2 laser). The device was laser
cut using a single AutoCAD mask with higher power for the
through cuts (power ¼ 40, speed ¼ 10, dpi ¼ 1000, 2 passes) and
lower power (power ¼ 28, speed ¼ 10, dpi ¼ 1000, 1 pass) for the
partial cuts. The units for the laser cutter settings are (power ¼ %
of max. power, i.e. 35 watt, speed ¼ % of max. speed, i.e. 26.5 in
sÀ1
, spatial resolution in dots per inch (dpi)).
Partial cuts were made from the top through the repositionable
adhesive layer. After laser cutting, the repositionable adhesive
layer was peeled from the bottom Mylar and card paper
substrate. This left the entire stack (Millipore cellulose paper -
card paper) in the regions that were cut with the lower power,
and only the substrate (card paper and bottom Mylar layer) in
the remaining areas. With this method we were able to fabricate
fluidic channels on a non-wicking substrate down to a width of
1 mm.
The remaining parts of the origami device were laser cut and
assembled by hand. The adhesive and spacers were formed by
laser cutting 3M Scotch mounting tape (3M, St. Paul, MN, USA)
(power ¼ 40, speed ¼ 10, dpi ¼ 1000, 3 passes). Millipore
cellulose paper was used to form the base of the sample-loading
cup and the contact stack, bound by the 3M Scotch mounting
tape for the sides of the cup and the contact stack. The Millipore
cellulose paper was laser cut with parameters power ¼ 10, speed
¼ 10, dpi ¼ 1000, 3 passes. The DNA capture filter was formed
from Fusion 5 membrane (Whatman Inc., Florham Park, NJ)
(laser cut with power ¼ 7, speed ¼ 7, dpi ¼ 1000, 1 pass). The
waste absorption pad (highly absorbent sterile sponge from
Dukal Corporation, Hauppauge NY, catalog# 6125) was hand
cut in 200
 200
squares. The waste absorption pad was stapled
onto the origami device on layer L1, with a contact stack placed
in the center so that the waste absorption pad maintains capillary
contact with the DNA binding filter. The dry reagent storage pad
was made from hand cutting an absorbent 100% pure cotton
non-woven fabric (Webril Handi-Pads from Fiberweb, Simp-
sonville, SC).
Dry lysis buffer storage
For dry reagent storage, wet lysis buffer (composition: 4.5M
guanidinium thiocyanate, 50 mM MES (2-(4-morpholino)-
ethane sulfonic acid) pH 5.5, 20 mM EDTA, 1% N-lauryl sar-
cosine (sodium salt), 5% Triton X-100 and 0.25M NaOH,
developed in house) was pipetted onto the buffer storage pad.
The pad was weighed after addition of the wet lysis buffer, dried
in a vacuum oven at 50
C for about 4 h and stored in a 45
C
incubator until needed (to simulate high temperature environ-
ments in the resource limited settings). The last step of device
assembly includes placing the dry lysis buffer storage pad on the
origami device using 3M Scotch mounting tape.
In our laboratory, the fabrication and the operation of the
microfluidic origami device were performed in different dedi-
cated spaces with the idea of translating the device production
and operation to the developing world while keeping the asso-
ciated costs to a minimum. We discuss these conditions and make
recommendations for high-volume production in a separate
section on avoiding contamination.
Experimental
Microfluidic origami device operation
The operation of the microfluidic origami device for NA
extraction is described in Fig. 3. (Please also refer to the
supplemental video†). The procedure is modified from our earlier
presentation20
to include rehydration of dry stored lysis buffer.
First a fresh DNA binding filter was placed on the microfluidic
origami device and the waste containment pad with the contact
stack (on L1) was folded below the filter. Next, the dry lysis
buffer storage pad (on L0) was rehydrated with nuclease-free
water (please note that the supplemental video shows rehydration
off the origami, however we have performed several instances of
rehydration on the origami device itself). The difference in the
weights of the buffer storage pad after addition of the wet buffer
and after drying was used to calculate the volume of water to be
added for rehydration. Approximately 490 ml of water was added
per 900 ml of wet lysis buffer for rehydration. The dry lysis buffer
was rehydrated for approximately 5 min. The raw sample (E.
coli-spiked mucin) was then loaded into the sample loading cup
(on layer L2, that folds directly above the filter). Next, the buffer
transport channel (made of Millipore cellulose paper on L3) was
folded above L2. The transport channel made contact with the
rehydrated lysis buffer storage pad and the raw sample that was
loaded into the cup. A contact stack was included in the design of
the transport channel to ensure that the lysis buffer reached the
bottom of the sample loading cup, as the viscous sample
‘‘decongested’’ (dissolved with no visible mucin chunks in the
sample loading cup) during lysis.
The lysis reagents flowed through the temporary fluidic
pathways without having to move the sample laterally through
the device, thus maximizing the DNA extraction efficiency. At
this point, complete (but as-yet-unoptimized) lysis of the sample
takes roughly 30 min. A weight was placed on the device in its
closed form during lysis to ensure contacts and capillary
wicking through layers L0–L3. L4 is reserved for integration of
future functionality and was not in use here. After lysis, the
weight was removed and the layers were unfolded to expose the
DNA binding filter on L0, with the waste containment pad still
folded beneath it. Since this is a paper device, the used layers L2
and L3 and the unused L4 layer were at this point cut off and
discarded in biohazard waste. This was done to facilitate ease of
operation and safety from exposure to harsh chemical residues
that resulted from chemical lysis. The DNA binding filter was
then washed with 100% ethanol to remove the protein and other
non-nucleic acid debris that could be bound to the filter. After
176 | Lab Chip, 2012, 12, 174–181 This journal is ª The Royal Society of Chemistry 2012
Publishedon08November2011.Downloadedon03/06/201416:12:34. View Article Online
5. the ethanol wash the filter was left to dry (for example, at room
temperature).
DNA elution and PCR analysis
After drying, the filter with the bound dry DNA was transferred
with a pair of sterile tweezers into a sterile syringe. A 150 ml
volume of low salt elute buffer (0.01 M Tris buffer, pH 8) was
introduced into the syringe and siphoned up and down, past the
DNA filter, using a sterile petri dish at the bottom. The filter was
allowed to soak in the elute buffer in the syringe for 5 min before
the extracted DNA was collected and stored in a nuclease-free
Eppendorf tube, ready for amplification by polymerase chain
reaction (PCR). The elutants from the microfluidic origami
contained both plasmid and genomic DNA (extracted by
a common procedure) that were amplifiable by a conventional
benchtop PCR machine (Perkin Elmer Cetus DNA Thermal
Cycler).
We used malB gene amplification product of 86 bp as a mar-
ker for E. coli genomic DNA. For genomic DNA amplification
the forward and reverse primers were EC3F: 50
-GCCGATGCC
AAATCGTCAG-30
and EC3R: 50
-GGCGAATACCCAGC
GACAT-30
. The PCR used for amplifying genomic DNA
incorporated an initial heat step at 95
C for 3 min followed by 38
cycles of 95
C for 10 s, 60
C for 10 s and 72
C for 15 s. Forward
and reverse primers used for the amplification of plasmid DNA
were S29: 50
- TCC CAG TCA CGA CGT - 30
and S33: 50
- AGC
CGA TAA CAA TTT CAC ACA GCA - 30
. The PCR thermal
process for plasmid DNA consisted of an initial heating step at
96
C for 2 min followed by 40 cycles of 96
C for 1 min, 52
C for
2 min and 70
C for 3 min (to detect low bacterial loads). For
samples spiked with undiluted bacterial culture, 27 cycles were
sufficient for detection of the extracted plasmid DNA. The
positive controls for PCR were Qiagen (Qiagen Inc. Valencia,
CA, USA) extracts from the E. coli culture (genomic extraction
control: QIAmp DNA Mini kit, plasmid extraction control:
QIAprep Spin Miniprep kit). The positive controls were pro-
cessed without mucin. The negative control was nuclease-free
water. For the plasmid extraction the ‘‘mucin only’’ lane served
as an additional negative control. PCR products were separated
using agarose gel electrophoresis and were visible in UV light
with ethidium bromide staining.
Bacterial load variation
The bacterial DNA extraction experiments to validate the
functioning of our device were from E. coli cultures. The E. coli
was grown overnight at 37
C in a shaker bath in Luria-Bertani
(LB) broth containing carbenicillin. E. coli cells containing the
plasmid DNA H127KSApuc18 are resistant to carbenicillin. In
order to test the lower limit of detection sensitivity with the
microfluidic origami extraction platform, a fresh culture was
grown overnight and was serially diluted in 10 fold steps. A
sample of 20 ml of each dilution was plated on LB-agar plates
(with carbenicillin) and grown overnight in a 37
C oven to
estimate the colonies grown on the plates. This was translated in
terms of colony forming units per ml (CFU mlÀ1
) of the grown
culture. 50 ml of each E. coli dilution was spiked in separate 250 ml
aliquots of porcine mucin. Each of these spiked raw mucin
samples was processed separately on a microfluidic origami
device.
Avoiding contamination
The fabrication of the microfluidic origami based sample prep-
aration device can be translated in high volumes to the
Fig. 3 Microfluidic origami operation: raw sample - DNA extraction 1.
Place fresh DNA binding filter on origami device (A). 2. Fold waste
absorption pad below the filter and place lysis buffer storage pad/rehy-
drate buffer (B). 3. Fold sample loading cup above DNA binding filter
and load sample into the cup (C). 4. Fold buffer transport channel (D). 5.
Place weight on closed microfluidic origami device to ensure contact and
capillarity during lysis operation ($ 30 min) (E). 6. Unfold origami and
cut and discard used/unwanted layers (F). 7. Wash DNA capture filter
directly with 100% ethanol (G). 8. Cut off waste absorption pad (H). 9.
Dry the DNA capture filter, e.g. on benchtop (I). 10. Elute DNA from
filter in low salt solution (J). Note: The microfluidic origami is a low cost
disposable device designed to process one sample per use. Gloves were
changed after each use. Please refer to the supplemental video.†
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6. developing world without a microfabrication laboratory
(referred to commonly as ‘‘cleanroom’’) – a typical environment
for the fabrication of most lab-on-a-chip systems. This cuts down
significantly the associated costs in maintaining the specialized
cleanroom equipment and environment (e.g. the particle count).
For this work, the origami device was fabricated in a dedicated
room that housed a laser cutter, an attached computer and
a work bench for assembly. The work bench was cleaned with
ethanol and isopropyl alcohol (IPA) prior to hand-assembling
laser cut portions of the origami device. The DNA binding filter
in particular was stored in a nuclease free Eppendorf tube,
immediately after laser cutting the factory sealed and shipped
Fusion 5 membrane (Whatman Inc., Florham Park, NJ). It was
placed on the origami device just before operation. For more
commercial type production and disease diagnosis, assembling
the laser cut portions of the device in a laminar flow bench fitted
with UV light and high-efficiency particulate air (HEPA) filters
would significantly reduce bacterial contamination. During
device operation, nuclease free Eppendorf tubes/containers and
sterile disposable sample applicators/syringes/tweezers should be
used for any intermediate sample or DNA binding filter
handling. In our laboratory protocol our dedicated sample
preparation space was wiped with ethanol and IPA before pro-
cessing a batch of samples. A fresh disposable diaper pad was
used below to contain any waste or possible spills. Tweezers/
sample applicators were sterilized between samples by washing
the tips with ethanol. Rinsing in DNase away, RNase away
solutions (Invitrogen, Carlsbad, CA) prevented NA degradation.
Personal protective equipment included gloves (to be changed for
every sample), labcoats, goggles, hairnets and facemasks.
Results and discussion
The sample size used in this work was 300 ml of pig mucin spiked
with E. coli. The origami-based POC sample preparation device
is designed to accommodate larger viscous sample sizes that are
readily available from the source and useful to detect lower or
sparser bacterial loads. Sample volumes can be downscaled, the
limiting factor of fluid flow being the minimum channel width
achievable by our fabrication method, which is currently 1 mm.
Reagent volumes are yet to be optimized, but we have observed
that 2 Â 900 ml volumes of lysis buffer are sufficient to dissolve
300 ml of viscous pig mucin. To facilitate ease of manual oper-
ation and to accommodate realistically useful viscous sample
sizes, our channel widths and lengths and filter and cup diameters
are of the order of 1–3.8 cm. We use the term microfluidic
because we rely on small-scale physical effects like capillarity and
have channel thicknesses and layer heights in the hundreds of mm
range.
The lysis buffer dissolves mucin at room temperature without
external power. It provides complete lysis of the E. coli bacterial
cells and does not inhibit PCR. The presence of a specific 500 bp
plasmid DNA band, seen after DNA extraction and amplifica-
tion only in E. coli-spiked mucin samples and not in unspiked
mucin samples (Fig. 4, Table 1) confirmed E. coli cell lysis and
DNA extraction from the spiked mucin matrix using the
microfluidic origami platform. Comparison between lanes 2–4
(extraction with rehydration of dry lysis buffer on the origami)
and lane 5 (extraction with direct wet lysis on the origami) in
Fig. 4 showed that there was no significant loss in detection due
to the buffer rehydration process.
Fig. 5 (Table 2) shows the extraction and amplification of
genomic (naturally occurring) DNA (malB gene of E. coli, 86
bp). For gel images in Fig. 4–Fig. 6 (Table 1–Table 3) note the
concurrence in the DNA band ‘‘expected’’ and ‘‘seen’’ columns.
The microfluidic origami approach features a raw sample to
DNA extraction time (lysis and wash time included) of about 1.5
h without the use of external power or between 45 min–1 h by
drying (post lysis and wash) on a heater block at 50
C or in an
oven at 37
C. In comparison, the raw-sample to extraction time
using the FTAÒ
cards5
is as follows: the raw sputum drying on
the FTAÒ
card takes 1 h, drying post washes takes another hour,
washing with the proprietary FTAÒ
purification reagent and the
TE buffer is about 25 min.
Bacterial load variation
Plasmid instead of genomic DNA was used in this work to
determine the limits of extraction and detection (after
Fig. 4 Extraction of plasmid DNA from raw sample at room temper-
ature, after rehydration of dry stored lysis buffer on microfluidic origami
device. Gel lane description given in Table 1.
Table 1 Lane description for Fig. 4
Lane 500 bp band expected
500 bp band
seen
1. Qiagen kit extraction of plasmid DNA from E. coli Yes (+ve control) Yes
2., 3. Mucin + E. coli with dry lysis rehydration (load $ 106
CFU mlÀ1
) Yes Yes
4. Mucin + E. coli with dry lysis rehydration (load $ 104
CFU mlÀ1
) Yes Yes
5. Mucin + E. coli with wet lysis Yes Yes
6. Mucin only No No
7. Water only No (-ve control) No
8. 100 bp Invitrogen ladder
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7. amplification). This is because the mucin used in this work,
derived from the porcine stomach, could possibly contain traces
of E. coli and would therefore not serve as a good negative
background for the bacterial load variation. We acknowledge
that diagnosis in a real world setting would be done with genomic
DNA and that a closer comparison to existing molecular diag-
nostic kits would result from using similar bacterial strains of the
disease with similar copy numbers. Our goal in this paper is to
introduce a low cost proof of concept platform for POC sample
preparation leading to POC molecular diagnosis.
Fig. 6 (Table 3) is representative of the bacterial load varia-
tions in this work. Plasmid DNA bands (500 bp), (after PCR)
were visible for the culture, a 10-fold culture dilution and a 100-
fold culture dilution. The corresponding bacterial load in the
spiked mucin sample as well as an estimate of the colony forming
units (CFU) in the actual spiked viscous mucin sample is given in
Table 3. These calculations were made from counting bacterial
colonies on agar plates.
The concentration of M. tuberculosis bacteria in clinical
sputum samples can vary from over 107
to less than 20 CFU
mlÀ1
.23
Though our present model is pig mucin spiked with
E. coli, our longer-term goal is low cost, POC sample preparation
for tuberculosis. We therefore compare our results with stan-
dards that are useful for culture-based tuberculosis diagnosis
(101
–103
bacilli mlÀ1
of sputum). However, diagnosis of tuber-
culosis by culture method normally takes 8–12 weeks with
additional time for disease subtyping in a national reference
laboratory specialized for culturing tuberculosis bacilli from
sputum samples. Added to this, culturing requires pretreatment
of sputum. The fully automated Cepheid GeneXpert MTB/RIF
protocol showed a 95% probability of detecting M. tuberculosis
in samples containing a bacterial load of at least 131 CFU mlÀ1
and was able to detect as few as 10 CFU mlÀ1
in 35% of the
samples22,24
with a raw sample to result time of less than 2 h.22,24
Our goal is to provide a very low cost, and yet effective means to
molecular diagnosis that will make disease sub-typing an
affordable reality in high disease burden, impoverished areas.
Table 2 Lane description for Fig. 5
Lane 86 bp band expected
86 bp band
seen
1. Qiagen kit extraction of genomic DNA from E. coli Yes (+ve control) Yes
2., 3. Mucin + E. coli with dry lysis rehydration (load $ 106
CFU/ml) Yes Yes
4. Mucin + E. coli with dry lysis rehydration (load $ 104
CFU/ml) Yes Yes
5. Mucin only (mucin is partially purified and may contain traces of E. coli) Maybe No
6. Water only No (-ve control) No
7. 50 bp Invitrogen ladder
Table 3 Lane description for Fig. 6
Lane
CFU in sample from
plating estimate CFU mlÀ1
of mucin
500 bp band
expected
500 bp band
seen
1. Qiagen kit extraction of plasmid DNA from E. coli (undiluted culture) +ve control Yes Yes
2. Mucin + E. coli 4200 1.4 Â 104
Yes Yes
3. Mucin + E. coli 485 1.6 Â 103
Yes Yes
4. Mucin + E. coli 25 83 Yes Yes
5. Mucin + E. coli 12 40 Yes Yes
6. Mucin + E. coli 10 33 Yes Yes
7. Mucin + E. coli 22 73 Yes Yes
8. Mucin only No No
9. Water only -ve control No No
10. 100 bp Invitrogen ladder
Fig. 5 Extraction of genomic DNA from raw sample at room temper-
ature, after rehydration of dry stored lysis buffer on microfluidic origami
device. Gel lane description given in Table 2.
Fig. 6 Bacterial load variation for DNA extraction on the microfluidic
origami device. Gel lane description given in Table 3.
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8. Our sample preparation method showed detection by molecular
diagnosis for a bacterial load as low as 33 CFU of E. coli mlÀ1
of
raw mucin. This low cost, origami-based sample preparation
method in combination with a portable NAAT-based system
should yield a raw sample-to-result point-of-care diagnosis in less
than 2 h.
Conclusions and future work
We have presented a low cost microfluidic origami device for
viscous sample preparation leading to point-of-care (POC)
molecular diagnosis. For this DNA extraction device, we set
ourselves the following design constraints:
1) Tolerance to a viscous sample matrix (mucus or blood).
2) Access to intermediate device layers at different times
during operation (in contrast to so-called programmable paper
diagnostics12
).
3) Ability to process raw samples in a POC setting (similar to
other lab-on-paper approaches to sample preparation5,6
).
4) Dry reagent storage for cell lysis and penetrating a viscous
sample matrix (similar to Guio’s approach with FTAÒ
cards5
).
5) Raw-sample to DNA extraction time of about 1.5 h without
the use of external power or within 1 h using an oven or heater
block after the lysis and wash steps.
6) Addition of minimal and safe liquid reagents to the origami
device to reduce chemical hazards during transport and handling
(in contrast to the protocol described by Guio for the FTAÒ
cards5
that requires the addition of a proprietary FTAÒ
purifi-
cation reagent and TE buffer, 10 mM Tris HCl, 0.1 mM EDTA
pH 8.0, to the chemically impregnated lysis paper).
7) Low cost device made from paper, Mylar and adhesives.
8) Freedom from the need to interface with permanent elec-
trical equipment (vortexer, centrifuge, controlled heater) or
Proteinase K (a PCR inhibitor) normally used in NA extraction
by commercial kits (e.g. Qiagen).
Our method offers the possibility of POC, room temperature,
NA extraction, followed by room temperature storage of the
extraction device for transport to more centralized diagnostic
facilities. This will potentially reduce the biohazard concerns
associated with the shipment of whole samples. Additionally it
will eliminate the cost of the cold chain, and sample fixing in the
absence of a portable PCR machine.
The fabrication and assembly of this microfluidic origami
device takes less than 30 min and can be adapted for high volume
production in the developing world without the expensive
overhead of a semiconductor cleanroom or microfabrication
laboratory facility—a typical environment for the fabrication of
lab-on-a-chip devices. All materials used in the fabrication and in
the formulation of the lysis buffer are commercially available.
The current prototype produces about 150 ml of concentrated
nucleic acid solution isolated from a raw sample, ready to be
transferred manually to another instrument.
Our sample preparation method allowed detection by molec-
ular amplification from a bacterial load as low as 33 CFU of
E. coli per ml of mucin, which falls in the lower limit for culture-
based diagnosis of Tuberculosis. This device holds promise for
affordable, specific and sensitive POC detection of diseases like
Tuberculosis, but we need to move from the E. coli-spiked
porcine mucin model system to human sputum loaded with M.
tuberculosis, a much more refractory organism. We plan to
approach this goal incrementally with the minimum of additional
processes on or off the microfluidic origami device. Our origami
based NA extraction device is designed to act as a low cost but
yet effective front end to a portable NA amplification device. The
design and working of the portable amplification and detection
device is outside of the scope of this paper.
This particular microfluidic origami device is also being
developed as a generic low cost, POC, nucleic acid extraction
device for samples of varying viscosities (sputum-urine) and
volumes (ml-ml) without the need of permanent electrical infra-
structure. We envision that the next generation of microfluidic
origami platforms will enable affordable molecular diagnosis and
disease sub-typing in geographically dispersed regions with high
disease burdens.
Acknowledgements
The authors would like to thank Prof. Patrick Stayton and Dr
Richard To for use of the PCR machine, and for donating the
transformed XL1-Blue E. coli strain and the primers for the
plasmid amplification. We thank Dr Richard To, Dr Barry Lutz,
Dr Elain Fu, Dr Paolo Spicar-Mihalic and Peter Kauffman for
insightful discussions. The primers used in this work for genomic
DNA amplification were from previous work done by the Yager
group with Micronics, Inc. This work was supported in part by
a gift from BigTec Labs, Bangalore, India to KFB and internal
funding by the University of Washington to PY and KFB.
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