disease diagnosis, types of diagnostic kits, nucleic acid based that include pcr, rt pcr, microarray, protein based which include ELISA, types of elisa, comparision among all types of diagnostic kits
The document discusses various types of polymerase chain reaction (PCR) techniques. It begins by explaining what PCR is and how it works to exponentially amplify DNA sequences. It then covers the history of PCR's invention and describes the basic components and steps of a PCR reaction. The document proceeds to discuss different PCR techniques like real-time PCR, asymmetric PCR, colony PCR, and nested PCR. It concludes by noting some applications and limitations of PCR.
This document discusses genome analysis and sequencing. It provides background on identifying genes and studying disease processes through genome sequencing. It also describes goals of identifying gene function through experiments and challenges like gene prediction and repetitive sequences. Specific projects aimed at tracking human genetic variations and the first bacterial genome sequencing are summarized. Criteria for selecting early genomes to sequence are outlined. Key differences between prokaryotic and eukaryotic genomes are noted, including the presence of chromosomes, repeats, introns and heterochromatin/euchromatin. Different types of repetitive sequences like satellites, minisatellites and microsatellites are defined. Transposable elements in eukaryotes are also briefly introduced.
Real time PCR allows for monitoring of DNA amplification during polymerase chain reaction (PCR), rather than just at the end. There are two main detection methods: using non-specific fluorescent dyes that bind to double stranded DNA, and using sequence-specific fluorescent probes. Common non-specific dyes include SYBR Green I, while TaqMan probes are an example of sequence-specific probes that use fluorescence resonance energy transfer. Real time PCR has applications in disease diagnosis, microbiology research on food and water safety, and quantifying gene expression levels.
Vaccine production involves growing viruses or bacteria and isolating antigens, purifying the antigens, inactivating pathogenic components, formulating the vaccine by adding adjuvants and preservatives, filling doses into syringes or vials, testing and releasing batches, and packaging and shipping with temperature monitoring to ensure vaccines remain effective. Vaccines are significant as they reduce global child mortality and provide life-saving immunization against deadly diseases worldwide.
Dr. Shamalamma S. presented on DNA microarrays. DNA microarrays allow thousands of genes to be compared simultaneously by attaching DNA probes to a chip which fluorescently labeled samples can bind to. The chip is then scanned to analyze gene expression levels. Applications include disease diagnosis, toxicology studies, and pharmacogenomics. While a powerful tool, microarrays have limitations such as lack of knowledge about many genes and lack of standardization.
Lateral flow assays (LFAs) are simple, rapid diagnostic tests that can detect target analytes in complex mixtures within 5-30 minutes. They work by capillary flow along a strip containing test and control lines with immobilized reagents. If the target analyte is present, it binds labeled reagents, typically colored nanoparticles, producing a visible test line. LFAs are widely used for medical testing, environmental monitoring, food safety testing and more due to their low cost, ease of use, and ability to be performed anywhere.
Metagenomics is the study of metagenome, genetics material, recovered directly from environmental sample such as soil, water or faeces.
Metagenomics is based on the genomics analysis of microbial DNA directly
from the communities present in samples
Metagenomics technology – genomics on a large scale will probably lead to great advances in medicine, agriculture, energy production and bioremediation.
Metagenomics can unlock the massive uncultured microbial diversity present in the environment for new molecule for therapeutic and biotechnological application.
Metagenomic studies have identified many novel microbial genes coding for metabolic pathways such as energy acquisition, carbon and nitrogen metabolism in natural environments that were previously considered to lack such metabolism
The document discusses different types of gene cloning vectors including plasmids, bacteriophages, cosmids, and phagemids. Plasmid vectors like pBR322 contain selectable markers and a multiple cloning site. Bacteriophage vectors like lambda phage infect bacteria and can carry larger DNA inserts. Cosmid vectors combine properties of plasmids and phages to clone fragments up to 50kb. All of these vector types allow cloning and replication of foreign DNA fragments in host cells.
The document discusses various types of polymerase chain reaction (PCR) techniques. It begins by explaining what PCR is and how it works to exponentially amplify DNA sequences. It then covers the history of PCR's invention and describes the basic components and steps of a PCR reaction. The document proceeds to discuss different PCR techniques like real-time PCR, asymmetric PCR, colony PCR, and nested PCR. It concludes by noting some applications and limitations of PCR.
This document discusses genome analysis and sequencing. It provides background on identifying genes and studying disease processes through genome sequencing. It also describes goals of identifying gene function through experiments and challenges like gene prediction and repetitive sequences. Specific projects aimed at tracking human genetic variations and the first bacterial genome sequencing are summarized. Criteria for selecting early genomes to sequence are outlined. Key differences between prokaryotic and eukaryotic genomes are noted, including the presence of chromosomes, repeats, introns and heterochromatin/euchromatin. Different types of repetitive sequences like satellites, minisatellites and microsatellites are defined. Transposable elements in eukaryotes are also briefly introduced.
Real time PCR allows for monitoring of DNA amplification during polymerase chain reaction (PCR), rather than just at the end. There are two main detection methods: using non-specific fluorescent dyes that bind to double stranded DNA, and using sequence-specific fluorescent probes. Common non-specific dyes include SYBR Green I, while TaqMan probes are an example of sequence-specific probes that use fluorescence resonance energy transfer. Real time PCR has applications in disease diagnosis, microbiology research on food and water safety, and quantifying gene expression levels.
Vaccine production involves growing viruses or bacteria and isolating antigens, purifying the antigens, inactivating pathogenic components, formulating the vaccine by adding adjuvants and preservatives, filling doses into syringes or vials, testing and releasing batches, and packaging and shipping with temperature monitoring to ensure vaccines remain effective. Vaccines are significant as they reduce global child mortality and provide life-saving immunization against deadly diseases worldwide.
Dr. Shamalamma S. presented on DNA microarrays. DNA microarrays allow thousands of genes to be compared simultaneously by attaching DNA probes to a chip which fluorescently labeled samples can bind to. The chip is then scanned to analyze gene expression levels. Applications include disease diagnosis, toxicology studies, and pharmacogenomics. While a powerful tool, microarrays have limitations such as lack of knowledge about many genes and lack of standardization.
Lateral flow assays (LFAs) are simple, rapid diagnostic tests that can detect target analytes in complex mixtures within 5-30 minutes. They work by capillary flow along a strip containing test and control lines with immobilized reagents. If the target analyte is present, it binds labeled reagents, typically colored nanoparticles, producing a visible test line. LFAs are widely used for medical testing, environmental monitoring, food safety testing and more due to their low cost, ease of use, and ability to be performed anywhere.
Metagenomics is the study of metagenome, genetics material, recovered directly from environmental sample such as soil, water or faeces.
Metagenomics is based on the genomics analysis of microbial DNA directly
from the communities present in samples
Metagenomics technology – genomics on a large scale will probably lead to great advances in medicine, agriculture, energy production and bioremediation.
Metagenomics can unlock the massive uncultured microbial diversity present in the environment for new molecule for therapeutic and biotechnological application.
Metagenomic studies have identified many novel microbial genes coding for metabolic pathways such as energy acquisition, carbon and nitrogen metabolism in natural environments that were previously considered to lack such metabolism
The document discusses different types of gene cloning vectors including plasmids, bacteriophages, cosmids, and phagemids. Plasmid vectors like pBR322 contain selectable markers and a multiple cloning site. Bacteriophage vectors like lambda phage infect bacteria and can carry larger DNA inserts. Cosmid vectors combine properties of plasmids and phages to clone fragments up to 50kb. All of these vector types allow cloning and replication of foreign DNA fragments in host cells.
Phage display technology allows the display of proteins or peptides on the outside of bacteriophages while encoding the corresponding gene on the inside. This allows for large libraries to be screened in vitro to select for interactions between the displayed molecules and a target. The most common phages used are filamentous phages like M13, which can be genetically manipulated to display proteins of interest. The technique involves inserting a gene into the phage coat protein gene, infecting bacteria to produce phage particles displaying the protein, and panning against a target to isolate interacting proteins.
What is Genome,Genome mapping,types of Genome mapping,linkage or genetic mapping,Physical mapping,Somatic cell hybridization
Radiation hybridization ,Fish( =fluorescence in - situ hybridization),Types of probes for FISH,applications,Molecular markers,Rflp(= Restriction fragment length polymorphism),RFLPs may have the following Applications;Advantages of rflp,disAdvantages of rflp, Rapd(=Random amplification of polymorphic DNA),Process of rapd, Difference between rflp &rapd
RT-PCR is a technique that uses reverse transcription to transcribe RNA into cDNA, which is then amplified using PCR. It allows for the detection and quantification of RNA. There are two main types: one-step RT-PCR, which performs reverse transcription and PCR in a single step, and two-step RT-PCR, which performs them as separate steps. RT-PCR is widely used in research, disease diagnosis, and detection of gene expression levels.
This document discusses various methods for preserving microorganisms in pure culture, including periodic transfer to fresh media, lyophilization (freeze drying), cryopreservation, storage under oil or in saline suspension, and drying in vacuum. The key objectives of preservation are to maintain isolated pure cultures for extended periods while avoiding contamination or genetic changes. Lyophilization and cryopreservation in liquid nitrogen are commonly used techniques that allow long-term viable storage for decades by stopping microbial growth and metabolism. Periodic transfer risks contamination and genetic variation over time.
Immunological techniques use antigens and antibodies to detect pathogens or their components in patient specimens. Agglutination tests couple antigens or antibodies to particles and look for cross-linking and agglutination. Complement fixation tests measure complement-consuming antibodies by incubating specimens with complement and antigens. Enzyme immunoassays like ELISA use enzyme-linked antibodies to detect antigens and quantify antibodies. Precipitation tests look for visible precipitation of antigen-antibody complexes to detect antigens or antibodies.
Fred Sanger developed the chain termination method of DNA sequencing that is still widely used today. It involves making multiple copies of a DNA fragment, conducting separate sequencing reactions with each of the four dideoxynucleotides, and using gel electrophoresis or capillary electrophoresis to determine the sequence based on fragment sizes. While it can sequence fragments up to 900 base pairs, Sanger sequencing is time-consuming and expensive for large genomes. However, it provides high quality sequence data and remains useful for targeted sequencing applications.
Electroporation is a method that uses electric pulses to create temporary pores in cell membranes, allowing molecules like DNA to enter cells. It can be used to introduce foreign genes into host cells for transformation or transfection. The electric pulses temporarily permeabilize the membrane, and the DNA enters through newly formed pores and incorporates into the host cell genome. Electroporation has applications in biotech for bacterial, yeast, and plant transformation, as well as gene therapy, cell therapy, and tumor treatment. It allows efficient delivery of DNA vaccines and other molecules into cells with minimal amounts of material.
Gene sequencing is the technique that determines the order of nucleotide bases in DNA. It allows researchers to read genetic information and understand genes. The first genome sequenced was a bacteriophage in 1977. Techniques have advanced from Sanger sequencing to second-generation sequencing using platforms like Illumina and third-generation single-molecule techniques. Gene sequencing has various applications in medicine, forensics, agriculture, cancer research and more. It is an important tool for understanding genomes and their relationship to traits and disease.
The document provides information about bacterial transformation. It describes that transformation is the process by which bacteria take up extracellular DNA from their environment. Frederick Griffith first discovered transformation in 1928 while working with pneumococcus bacteria. His experiments showed that a non-virulent rough form could be transformed into a virulent smooth form by DNA from a heat-killed smooth strain. Later experiments by Avery, Macleod and McCarty demonstrated that DNA is the transforming principle and genetic material of bacteria. The document then discusses various methods of bacterial transformation including chemical and physical methods like electroporation and use of calcium chloride. It also explains the molecular mechanism of transformation involving DNA binding, penetration, synapsis formation and integration into the bacterial chromosome.
This document discusses vaccines, including their history, types, production methods, and components. It explains that vaccines induce immunity by triggering an antibody response to antigens from weakened or killed disease-causing microorganisms. Vaccines are produced using live attenuated microbes, inactivated pathogens, recombinant DNA technology, or as mixtures targeting multiple diseases. Large-scale production involves growing microbes, inactivating or attenuating them, and adding stabilizers or adjuvants to the purified antigen formulations.
This document discusses restriction enzymes, including their discovery, types, subunits, nomenclature, recognition sequences, properties, and applications. Restriction enzymes are bacterial enzymes that cut DNA at specific recognition sequences. There are three main types - Type I cut DNA randomly, Type II cut within or near their recognition sequences, and Type III cut nearby. They are used in gene cloning, protein expression, DNA manipulation, and studying DNA sequences.
Bioprocess development and technology-Introduction,History of bioprocess,Milestones of Bioprocess development,Bioprocess development,Impact on Biotechnology
Nucleic acid based microbial diagnostic techniquesAfra Fathima
Nucleic acid-based diagnostic techniques can detect pathogens by identifying their DNA or RNA. Common techniques include PCR/RT-PCR, which amplifies DNA/cDNA, isothermal amplification, and hybridization. Sequencing provides more detailed information but requires more resources. A technique called QBRDA uses magnetic beads and Q-Beta replicase to amplify target nucleic acids, allowing detection of as few as 1,000 molecules. It was tested on urogenital samples and detected Chlamydia trachomatis similarly to culture.
Satellite viruses are sub-viral agents that depend on a helper virus for replication. The first reported satellite virus was Tobacco necrosis satellite virus. Satellite viruses contain nucleic acids enclosed in a protein coat and lack genes for replication. Satellite genomes can be single-stranded RNA, DNA, or circular RNA.
Satellite RNAs are small, linear or circular RNA strands found in certain multicomponent virus particles. They do not encode their own coat protein and depend on a helper virus for replication and encapsidation.
Viroids were discovered in 1971 and are small, circular, naked RNA molecules that replicate independently using host polymerases. Well-studied viroids include potato spindle tuber viroid and av
The document summarizes a seminar on the Ti plasmid. It discusses that the Ti plasmid is found in Agrobacterium tumefaciens and is responsible for crown gall tumor formation in plants. It describes the organization and structure of the Ti plasmid, including the T-DNA region flanked by borders that is transferred to plant cells. Two common vector systems used for plant transformation, the cointegrate vector and binary vector, are explained. The cointegrate vector involves integration of an intermediate vector with the Ti plasmid, while the binary vector separates the plasmid and virulence genes. Finally, the general process of Agrobacterium-mediated plant transformation is outlined.
This document summarizes the process of colony hybridization. Colony hybridization allows researchers to select bacterial colonies containing specific genes. The procedure involves lysing bacterial colonies on a nitrocellulose filter, denaturing the DNA, and hybridizing the DNA to a labeled probe for the target gene. Unbound probe is then washed away. Where the probe binds to colonies containing the target gene, dark spots will appear on an x-ray film placed over the filter, allowing identification of recombinant colonies containing the desired gene. Colony hybridization has applications in identifying recombinant bacteria, cytogenetics studies, disease diagnosis, fingerprinting, and screening bacterial colonies.
The document discusses different expression vectors and systems used for recombinant protein expression. It describes key elements required for an expression vector including an origin of replication, selective marker, promoter, multiple cloning site, and terminator. It provides details on commonly used expression systems in E. coli such as the lac, tac, lambda PL, and T7 promoters. It also summarizes protein expression in yeast using the galactose-inducible GAL promoter system.
Vectors are DNA molecules that can deliver foreign DNA into host cells. The main types of vectors are plasmids, bacteriophages, cosmids, and phagemids. Plasmids are circular, self-replicating DNA molecules that are commonly used as vectors. Key plasmid vectors include pBR322, which contains antibiotic resistance genes, and pUC18/19, which are smaller and contain an ampicillin resistance gene. Bacteriophage vectors like lambda phage and M13 phage can incorporate larger DNA fragments. Cosmids are hybrid vectors that contain phage and plasmid elements, allowing them to replicate like plasmids. Shuttle vectors contain origins of replication from different species, allowing replication in multiple host
This document discusses various blotting techniques used to detect and analyze biomolecules like DNA, RNA, and proteins. It describes the Southern blot technique developed by Edwin Southern used to detect specific DNA sequences. It also discusses the Northern blot technique used to detect RNA, developed by James Alwine and George Stark. Finally, it summarizes the Western blot technique used to detect specific proteins by using antibodies, developed in 1981. These blotting techniques allow separation and detection of biomolecules through transfer and hybridization/binding reactions.
Moleecular mechanism of disease diagnosisjeeva raj
This document discusses molecular techniques for disease diagnosis, including antibody-based and nucleic acid-based methods. Antibody-based methods include using polyclonal and monoclonal antibodies in techniques like ELISA and lateral flow. PCR and RAPD are described as nucleic acid-based techniques that use primers and DNA amplification to detect pathogens. DNA microarrays are also mentioned as a diagnostic tool that screens for multiple pathogens by probing arrays of known DNA sequences.
This document discusses advanced diagnostic aids in periodontology. It describes conventional diagnosis methods and their limitations. Newer diagnostic methods discussed include gingival bleeding assessment, gingival temperature measurement, improved periodontal probing, digital radiography, subtraction radiography, microbiological analysis using bacterial culture, microscopy, immunodiagnostic assays, enzymatic methods, DNA probes, and methods to characterize the host inflammatory response using biomarkers. Overall, the document outlines many potential diagnostic markers and tests but notes that more research is still needed to identify simple, predictive, and cost-effective tests to complement clinical diagnosis in periodontology.
Phage display technology allows the display of proteins or peptides on the outside of bacteriophages while encoding the corresponding gene on the inside. This allows for large libraries to be screened in vitro to select for interactions between the displayed molecules and a target. The most common phages used are filamentous phages like M13, which can be genetically manipulated to display proteins of interest. The technique involves inserting a gene into the phage coat protein gene, infecting bacteria to produce phage particles displaying the protein, and panning against a target to isolate interacting proteins.
What is Genome,Genome mapping,types of Genome mapping,linkage or genetic mapping,Physical mapping,Somatic cell hybridization
Radiation hybridization ,Fish( =fluorescence in - situ hybridization),Types of probes for FISH,applications,Molecular markers,Rflp(= Restriction fragment length polymorphism),RFLPs may have the following Applications;Advantages of rflp,disAdvantages of rflp, Rapd(=Random amplification of polymorphic DNA),Process of rapd, Difference between rflp &rapd
RT-PCR is a technique that uses reverse transcription to transcribe RNA into cDNA, which is then amplified using PCR. It allows for the detection and quantification of RNA. There are two main types: one-step RT-PCR, which performs reverse transcription and PCR in a single step, and two-step RT-PCR, which performs them as separate steps. RT-PCR is widely used in research, disease diagnosis, and detection of gene expression levels.
This document discusses various methods for preserving microorganisms in pure culture, including periodic transfer to fresh media, lyophilization (freeze drying), cryopreservation, storage under oil or in saline suspension, and drying in vacuum. The key objectives of preservation are to maintain isolated pure cultures for extended periods while avoiding contamination or genetic changes. Lyophilization and cryopreservation in liquid nitrogen are commonly used techniques that allow long-term viable storage for decades by stopping microbial growth and metabolism. Periodic transfer risks contamination and genetic variation over time.
Immunological techniques use antigens and antibodies to detect pathogens or their components in patient specimens. Agglutination tests couple antigens or antibodies to particles and look for cross-linking and agglutination. Complement fixation tests measure complement-consuming antibodies by incubating specimens with complement and antigens. Enzyme immunoassays like ELISA use enzyme-linked antibodies to detect antigens and quantify antibodies. Precipitation tests look for visible precipitation of antigen-antibody complexes to detect antigens or antibodies.
Fred Sanger developed the chain termination method of DNA sequencing that is still widely used today. It involves making multiple copies of a DNA fragment, conducting separate sequencing reactions with each of the four dideoxynucleotides, and using gel electrophoresis or capillary electrophoresis to determine the sequence based on fragment sizes. While it can sequence fragments up to 900 base pairs, Sanger sequencing is time-consuming and expensive for large genomes. However, it provides high quality sequence data and remains useful for targeted sequencing applications.
Electroporation is a method that uses electric pulses to create temporary pores in cell membranes, allowing molecules like DNA to enter cells. It can be used to introduce foreign genes into host cells for transformation or transfection. The electric pulses temporarily permeabilize the membrane, and the DNA enters through newly formed pores and incorporates into the host cell genome. Electroporation has applications in biotech for bacterial, yeast, and plant transformation, as well as gene therapy, cell therapy, and tumor treatment. It allows efficient delivery of DNA vaccines and other molecules into cells with minimal amounts of material.
Gene sequencing is the technique that determines the order of nucleotide bases in DNA. It allows researchers to read genetic information and understand genes. The first genome sequenced was a bacteriophage in 1977. Techniques have advanced from Sanger sequencing to second-generation sequencing using platforms like Illumina and third-generation single-molecule techniques. Gene sequencing has various applications in medicine, forensics, agriculture, cancer research and more. It is an important tool for understanding genomes and their relationship to traits and disease.
The document provides information about bacterial transformation. It describes that transformation is the process by which bacteria take up extracellular DNA from their environment. Frederick Griffith first discovered transformation in 1928 while working with pneumococcus bacteria. His experiments showed that a non-virulent rough form could be transformed into a virulent smooth form by DNA from a heat-killed smooth strain. Later experiments by Avery, Macleod and McCarty demonstrated that DNA is the transforming principle and genetic material of bacteria. The document then discusses various methods of bacterial transformation including chemical and physical methods like electroporation and use of calcium chloride. It also explains the molecular mechanism of transformation involving DNA binding, penetration, synapsis formation and integration into the bacterial chromosome.
This document discusses vaccines, including their history, types, production methods, and components. It explains that vaccines induce immunity by triggering an antibody response to antigens from weakened or killed disease-causing microorganisms. Vaccines are produced using live attenuated microbes, inactivated pathogens, recombinant DNA technology, or as mixtures targeting multiple diseases. Large-scale production involves growing microbes, inactivating or attenuating them, and adding stabilizers or adjuvants to the purified antigen formulations.
This document discusses restriction enzymes, including their discovery, types, subunits, nomenclature, recognition sequences, properties, and applications. Restriction enzymes are bacterial enzymes that cut DNA at specific recognition sequences. There are three main types - Type I cut DNA randomly, Type II cut within or near their recognition sequences, and Type III cut nearby. They are used in gene cloning, protein expression, DNA manipulation, and studying DNA sequences.
Bioprocess development and technology-Introduction,History of bioprocess,Milestones of Bioprocess development,Bioprocess development,Impact on Biotechnology
Nucleic acid based microbial diagnostic techniquesAfra Fathima
Nucleic acid-based diagnostic techniques can detect pathogens by identifying their DNA or RNA. Common techniques include PCR/RT-PCR, which amplifies DNA/cDNA, isothermal amplification, and hybridization. Sequencing provides more detailed information but requires more resources. A technique called QBRDA uses magnetic beads and Q-Beta replicase to amplify target nucleic acids, allowing detection of as few as 1,000 molecules. It was tested on urogenital samples and detected Chlamydia trachomatis similarly to culture.
Satellite viruses are sub-viral agents that depend on a helper virus for replication. The first reported satellite virus was Tobacco necrosis satellite virus. Satellite viruses contain nucleic acids enclosed in a protein coat and lack genes for replication. Satellite genomes can be single-stranded RNA, DNA, or circular RNA.
Satellite RNAs are small, linear or circular RNA strands found in certain multicomponent virus particles. They do not encode their own coat protein and depend on a helper virus for replication and encapsidation.
Viroids were discovered in 1971 and are small, circular, naked RNA molecules that replicate independently using host polymerases. Well-studied viroids include potato spindle tuber viroid and av
The document summarizes a seminar on the Ti plasmid. It discusses that the Ti plasmid is found in Agrobacterium tumefaciens and is responsible for crown gall tumor formation in plants. It describes the organization and structure of the Ti plasmid, including the T-DNA region flanked by borders that is transferred to plant cells. Two common vector systems used for plant transformation, the cointegrate vector and binary vector, are explained. The cointegrate vector involves integration of an intermediate vector with the Ti plasmid, while the binary vector separates the plasmid and virulence genes. Finally, the general process of Agrobacterium-mediated plant transformation is outlined.
This document summarizes the process of colony hybridization. Colony hybridization allows researchers to select bacterial colonies containing specific genes. The procedure involves lysing bacterial colonies on a nitrocellulose filter, denaturing the DNA, and hybridizing the DNA to a labeled probe for the target gene. Unbound probe is then washed away. Where the probe binds to colonies containing the target gene, dark spots will appear on an x-ray film placed over the filter, allowing identification of recombinant colonies containing the desired gene. Colony hybridization has applications in identifying recombinant bacteria, cytogenetics studies, disease diagnosis, fingerprinting, and screening bacterial colonies.
The document discusses different expression vectors and systems used for recombinant protein expression. It describes key elements required for an expression vector including an origin of replication, selective marker, promoter, multiple cloning site, and terminator. It provides details on commonly used expression systems in E. coli such as the lac, tac, lambda PL, and T7 promoters. It also summarizes protein expression in yeast using the galactose-inducible GAL promoter system.
Vectors are DNA molecules that can deliver foreign DNA into host cells. The main types of vectors are plasmids, bacteriophages, cosmids, and phagemids. Plasmids are circular, self-replicating DNA molecules that are commonly used as vectors. Key plasmid vectors include pBR322, which contains antibiotic resistance genes, and pUC18/19, which are smaller and contain an ampicillin resistance gene. Bacteriophage vectors like lambda phage and M13 phage can incorporate larger DNA fragments. Cosmids are hybrid vectors that contain phage and plasmid elements, allowing them to replicate like plasmids. Shuttle vectors contain origins of replication from different species, allowing replication in multiple host
This document discusses various blotting techniques used to detect and analyze biomolecules like DNA, RNA, and proteins. It describes the Southern blot technique developed by Edwin Southern used to detect specific DNA sequences. It also discusses the Northern blot technique used to detect RNA, developed by James Alwine and George Stark. Finally, it summarizes the Western blot technique used to detect specific proteins by using antibodies, developed in 1981. These blotting techniques allow separation and detection of biomolecules through transfer and hybridization/binding reactions.
Moleecular mechanism of disease diagnosisjeeva raj
This document discusses molecular techniques for disease diagnosis, including antibody-based and nucleic acid-based methods. Antibody-based methods include using polyclonal and monoclonal antibodies in techniques like ELISA and lateral flow. PCR and RAPD are described as nucleic acid-based techniques that use primers and DNA amplification to detect pathogens. DNA microarrays are also mentioned as a diagnostic tool that screens for multiple pathogens by probing arrays of known DNA sequences.
This document discusses advanced diagnostic aids in periodontology. It describes conventional diagnosis methods and their limitations. Newer diagnostic methods discussed include gingival bleeding assessment, gingival temperature measurement, improved periodontal probing, digital radiography, subtraction radiography, microbiological analysis using bacterial culture, microscopy, immunodiagnostic assays, enzymatic methods, DNA probes, and methods to characterize the host inflammatory response using biomarkers. Overall, the document outlines many potential diagnostic markers and tests but notes that more research is still needed to identify simple, predictive, and cost-effective tests to complement clinical diagnosis in periodontology.
Identification and Detection of Microorganism esraa alaa
Molecular detection of pathogens (molecular microbiology)
is a new, dynamic and progressive spinoff of classic microbiology. It plays an important role in those clinical situations when standard microbiology (relying on the successful cultivation of potential pathogens) produces suboptimal results or completely fails.
OR
Modern approach for identification and quantification of microorganisms (pathogens) in the diagnostics of infections or foodborne illness using molecular microbiology. Broadest range of available tests and tailor-made packages.
Advances in diagnostic technology allow for more sensitive, specific, rapid and cost-effective diagnosis of diseases. New methods like PCR, real-time PCR, in situ hybridization, biosensors, infrared thermography, and ELISA have improved on classical diagnostic approaches by being able to detect minute amounts of pathogens, identify pathogens rapidly, and differentiate between field strains and vaccine strains. These advanced diagnostic techniques are important for disease control, treatment, and surveillance.
Bacterial genetics - Clinical applications, by Dr. Himanshu KhatriDrHimanshuKhatri
This document discusses several topics in bacterial genetics and their clinical applications:
1. It describes mechanisms of inherent and acquired drug resistance in bacteria. Acquired resistance can occur through spontaneous mutation or horizontal gene transfer.
2. Molecular diagnostic methods like nucleic acid probes, PCR, and RFLP can be used to identify and type bacteria. PCR allows detection of small amounts of bacterial nucleic acids.
3. Genetic engineering techniques allow isolation of bacterial genes and production of useful proteins like insulin through recombinant DNA technology.
Molecular methods and clinical microbiologyimprovemed
This document discusses various molecular diagnostic methods used in clinical microbiology. It describes techniques such as nucleic acid hybridization, polymerase chain reaction (PCR), and real-time PCR which can directly detect microorganisms, identify pathogens, and detect antibiotic resistance genes. The advantages of these molecular methods include speed, ability to detect fastidious or non-culturable bacteria, and quantitative analysis. However, limitations include possible false negatives from inhibitors and inability to determine bacterial viability. Overall, molecular diagnostics provide crucial information to improve patient treatment and conduct epidemiological analyses.
Food borne pathogens causes various diseases. So it is very important to detect them. Rapid methods help to detect pathogens in a very short period of time.
This document discusses several methods for identifying viruses, including cell culture-based identification using cytopathic effects, hemagglutination assays, nucleic acid amplification tests like PCR, enzyme immunoassays, immunofluorescence assays, molecular methods, viral plaque assays, and quantal assays like TCID50 that determine infectious viral titers. It provides details on how each method works and what types of information can be obtained about viruses using these techniques.
Optical sensors, especially RGB imaging sensors, show potential for plant disease detection. RGB sensors utilize visible light to detect color changes caused by biotic stresses like diseases. Digital images from RGB sensors can be analyzed using software to identify disease symptoms and quantify severity. Early detection of diseases using optical sensors allows targeted treatment and reduces economic and environmental impacts of agriculture.
PCR & It's Various Types, DNA chip method & Serological methods of Seed Healt...Prajwal Gowda M.A
The document discusses various advances in seed health testing methods, including nucleic acid-based methods like PCR and DNA chip technology, as well as serological methods like ELISA, radioimmunoassay, and immunofluorescence microscopy. It provides details on how PCR works, including nucleic acid extraction, amplification through repeated heating and cooling cycles, and product analysis through gel electrophoresis. It also summarizes several PCR-based methods and discusses DNA chip technology. Limitations of these methods are noted.
This document discusses techniques for detecting and identifying plant viruses in quarantine. It covers:
1. An overview of plant viruses, their characteristics and modes of transmission.
2. Various detection techniques including biological, physical, biochemical, serological and molecular methods. Serological techniques include ELISA and molecular methods include PCR, RT-PCR and real-time PCR.
3. Details on techniques like mechanical inoculation, electron microscopy, and nucleic acid-based methods.
4. The use of these techniques to detect and identify important quarantine viruses.
This document provides an overview of molecular techniques used in microbiology. It discusses three main categories: signal amplification methods like nucleic acid probes; nucleic acid amplification techniques like PCR and its variants; and strain typing methods. PCR and its applications are described in detail, including real-time PCR. Other amplification methods and post-amplification analysis techniques like gel electrophoresis and sequencing are also summarized. Commonly used commercial systems like BioFire FilmArray that employ multiplex PCR are highlighted.
Viral Cultivation and Identification Technique.pptxMagAhmed
Viral cultivation techniques allow identification and diagnosis of viruses from clinical specimens. Viruses can be grown in embryonated eggs, experimental animals, or tissue culture. Identification is confirmed using polymerase chain reaction (PCR) or enzyme-linked immunosorbent assay (ELISA) tests. Rapid diagnostic tests can also detect certain infections at the point-of-care. While older methods like viral microscopy are being replaced, these diagnostic techniques remain important for diagnosing and understanding infectious diseases.
Techniques for identification of bacterial and viral pathogensAmbica Bora
This document discusses various techniques for identifying bacterial and viral pathogens. It covers microscopic, histological, microbiological, immunological, and molecular techniques.
Microscopic techniques include basic staining methods to identify organisms under a microscope. Histological techniques examine stained tissue sections to detect pathogens. Microbiological techniques involve culturing samples and conducting biochemical tests on isolates.
Immunological techniques like ELISA, agglutination, and immunofluorescence use antigen-antibody reactions for detection. Molecular techniques like PCR, multiplex PCR, and DNA microarrays allow sensitive detection and differentiation of pathogens through nucleic acid analysis.
After detection, antibiotics are usually administered but alternative remedies like photoinactivation of pathogens using blue light and bacteri
The document summarizes molecular diagnostic techniques for detecting plant pathogens. It discusses several techniques including polymerase chain reaction (PCR), molecular hybridization, molecular markers, nucleic acid sequencing, and microarrays. PCR is described as a sensitive technique that can amplify DNA from pathogens. Molecular hybridization uses probes to detect complementary DNA or RNA sequences from pathogens. Molecular markers like RFLP and RAPD can identify pathogens by detecting DNA polymorphisms. Nucleic acid sequencing techniques like NASBA and LAMP can detect and amplify RNA from pathogens. Microarrays allow simultaneous detection of multiple pathogens using DNA probes spotted onto a chip.
This document provides an introduction and overview of artificial intelligence applications in plant disease detection. It discusses how machine learning and deep learning are being used to identify plant diseases through image recognition. Examples of algorithms commonly used include convolutional neural networks, recurrent neural networks, and support vector machines. The scope of AI in agriculture is also summarized, including how IoT sensor data, drone images, and automation can be used for tasks like crop monitoring, irrigation, and recommending optimal agricultural practices. Machine learning is also being applied to disease predictions and molecular-level interactions between plants and pathogens.
Microbiome Identification to Characterization: Pathogen Detection Webinar Ser...QIAGEN
This document discusses the development of rapid detection methods for microbial and microbiome analysis and their applications to human health. It provides an overview of QIAGEN's microbial qPCR products and discusses focused metagenomics applications like screening for antibiotic resistance genes in the food supply and human gut. Limitations of current methods are outlined and the benefits of qPCR for rapid, specific, and sensitive microbial detection are described.
The cost of acquiring information by natural selectionCarl Bergstrom
This is a short talk that I gave at the Banff International Research Station workshop on Modeling and Theory in Population Biology. The idea is to try to understand how the burden of natural selection relates to the amount of information that selection puts into the genome.
It's based on the first part of this research paper:
The cost of information acquisition by natural selection
Ryan Seamus McGee, Olivia Kosterlitz, Artem Kaznatcheev, Benjamin Kerr, Carl T. Bergstrom
bioRxiv 2022.07.02.498577; doi: https://doi.org/10.1101/2022.07.02.498577
Discovery of An Apparent Red, High-Velocity Type Ia Supernova at 𝐳 = 2.9 wi...Sérgio Sacani
We present the JWST discovery of SN 2023adsy, a transient object located in a host galaxy JADES-GS
+
53.13485
−
27.82088
with a host spectroscopic redshift of
2.903
±
0.007
. The transient was identified in deep James Webb Space Telescope (JWST)/NIRCam imaging from the JWST Advanced Deep Extragalactic Survey (JADES) program. Photometric and spectroscopic followup with NIRCam and NIRSpec, respectively, confirm the redshift and yield UV-NIR light-curve, NIR color, and spectroscopic information all consistent with a Type Ia classification. Despite its classification as a likely SN Ia, SN 2023adsy is both fairly red (
�
(
�
−
�
)
∼
0.9
) despite a host galaxy with low-extinction and has a high Ca II velocity (
19
,
000
±
2
,
000
km/s) compared to the general population of SNe Ia. While these characteristics are consistent with some Ca-rich SNe Ia, particularly SN 2016hnk, SN 2023adsy is intrinsically brighter than the low-
�
Ca-rich population. Although such an object is too red for any low-
�
cosmological sample, we apply a fiducial standardization approach to SN 2023adsy and find that the SN 2023adsy luminosity distance measurement is in excellent agreement (
≲
1
�
) with
Λ
CDM. Therefore unlike low-
�
Ca-rich SNe Ia, SN 2023adsy is standardizable and gives no indication that SN Ia standardized luminosities change significantly with redshift. A larger sample of distant SNe Ia is required to determine if SN Ia population characteristics at high-
�
truly diverge from their low-
�
counterparts, and to confirm that standardized luminosities nevertheless remain constant with redshift.
The debris of the ‘last major merger’ is dynamically youngSérgio Sacani
The Milky Way’s (MW) inner stellar halo contains an [Fe/H]-rich component with highly eccentric orbits, often referred to as the
‘last major merger.’ Hypotheses for the origin of this component include Gaia-Sausage/Enceladus (GSE), where the progenitor
collided with the MW proto-disc 8–11 Gyr ago, and the Virgo Radial Merger (VRM), where the progenitor collided with the
MW disc within the last 3 Gyr. These two scenarios make different predictions about observable structure in local phase space,
because the morphology of debris depends on how long it has had to phase mix. The recently identified phase-space folds in Gaia
DR3 have positive caustic velocities, making them fundamentally different than the phase-mixed chevrons found in simulations
at late times. Roughly 20 per cent of the stars in the prograde local stellar halo are associated with the observed caustics. Based
on a simple phase-mixing model, the observed number of caustics are consistent with a merger that occurred 1–2 Gyr ago.
We also compare the observed phase-space distribution to FIRE-2 Latte simulations of GSE-like mergers, using a quantitative
measurement of phase mixing (2D causticality). The observed local phase-space distribution best matches the simulated data
1–2 Gyr after collision, and certainly not later than 3 Gyr. This is further evidence that the progenitor of the ‘last major merger’
did not collide with the MW proto-disc at early times, as is thought for the GSE, but instead collided with the MW disc within
the last few Gyr, consistent with the body of work surrounding the VRM.
Candidate young stellar objects in the S-cluster: Kinematic analysis of a sub...Sérgio Sacani
Context. The observation of several L-band emission sources in the S cluster has led to a rich discussion of their nature. However, a definitive answer to the classification of the dusty objects requires an explanation for the detection of compact Doppler-shifted Brγ emission. The ionized hydrogen in combination with the observation of mid-infrared L-band continuum emission suggests that most of these sources are embedded in a dusty envelope. These embedded sources are part of the S-cluster, and their relationship to the S-stars is still under debate. To date, the question of the origin of these two populations has been vague, although all explanations favor migration processes for the individual cluster members. Aims. This work revisits the S-cluster and its dusty members orbiting the supermassive black hole SgrA* on bound Keplerian orbits from a kinematic perspective. The aim is to explore the Keplerian parameters for patterns that might imply a nonrandom distribution of the sample. Additionally, various analytical aspects are considered to address the nature of the dusty sources. Methods. Based on the photometric analysis, we estimated the individual H−K and K−L colors for the source sample and compared the results to known cluster members. The classification revealed a noticeable contrast between the S-stars and the dusty sources. To fit the flux-density distribution, we utilized the radiative transfer code HYPERION and implemented a young stellar object Class I model. We obtained the position angle from the Keplerian fit results; additionally, we analyzed the distribution of the inclinations and the longitudes of the ascending node. Results. The colors of the dusty sources suggest a stellar nature consistent with the spectral energy distribution in the near and midinfrared domains. Furthermore, the evaporation timescales of dusty and gaseous clumps in the vicinity of SgrA* are much shorter ( 2yr) than the epochs covered by the observations (≈15yr). In addition to the strong evidence for the stellar classification of the D-sources, we also find a clear disk-like pattern following the arrangements of S-stars proposed in the literature. Furthermore, we find a global intrinsic inclination for all dusty sources of 60 ± 20◦, implying a common formation process. Conclusions. The pattern of the dusty sources manifested in the distribution of the position angles, inclinations, and longitudes of the ascending node strongly suggests two different scenarios: the main-sequence stars and the dusty stellar S-cluster sources share a common formation history or migrated with a similar formation channel in the vicinity of SgrA*. Alternatively, the gravitational influence of SgrA* in combination with a massive perturber, such as a putative intermediate mass black hole in the IRS 13 cluster, forces the dusty objects and S-stars to follow a particular orbital arrangement. Key words. stars: black holes– stars: formation– Galaxy: center– galaxies: star formation
ESA/ACT Science Coffee: Diego Blas - Gravitational wave detection with orbita...Advanced-Concepts-Team
Presentation in the Science Coffee of the Advanced Concepts Team of the European Space Agency on the 07.06.2024.
Speaker: Diego Blas (IFAE/ICREA)
Title: Gravitational wave detection with orbital motion of Moon and artificial
Abstract:
In this talk I will describe some recent ideas to find gravitational waves from supermassive black holes or of primordial origin by studying their secular effect on the orbital motion of the Moon or satellites that are laser ranged.
Sexuality - Issues, Attitude and Behaviour - Applied Social Psychology - Psyc...PsychoTech Services
A proprietary approach developed by bringing together the best of learning theories from Psychology, design principles from the world of visualization, and pedagogical methods from over a decade of training experience, that enables you to: Learn better, faster!
JAMES WEBB STUDY THE MASSIVE BLACK HOLE SEEDSSérgio Sacani
The pathway(s) to seeding the massive black holes (MBHs) that exist at the heart of galaxies in the present and distant Universe remains an unsolved problem. Here we categorise, describe and quantitatively discuss the formation pathways of both light and heavy seeds. We emphasise that the most recent computational models suggest that rather than a bimodal-like mass spectrum between light and heavy seeds with light at one end and heavy at the other that instead a continuum exists. Light seeds being more ubiquitous and the heavier seeds becoming less and less abundant due the rarer environmental conditions required for their formation. We therefore examine the different mechanisms that give rise to different seed mass spectrums. We show how and why the mechanisms that produce the heaviest seeds are also among the rarest events in the Universe and are hence extremely unlikely to be the seeds for the vast majority of the MBH population. We quantify, within the limits of the current large uncertainties in the seeding processes, the expected number densities of the seed mass spectrum. We argue that light seeds must be at least 103 to 105 times more numerous than heavy seeds to explain the MBH population as a whole. Based on our current understanding of the seed population this makes heavy seeds (Mseed > 103 M⊙) a significantly more likely pathway given that heavy seeds have an abundance pattern than is close to and likely in excess of 10−4 compared to light seeds. Finally, we examine the current state-of-the-art in numerical calculations and recent observations and plot a path forward for near-future advances in both domains.
2. Introduction
• Annual losses by diseases: ˃42%
• Diagnosis of plant disease is to identify the disease nature and to
determine the causal agent whether living or non living
• Traditional method -: Visual examination. possible only after major
damage has already done
• To save plants from irreparable damage by pathogens, infection should
be identified even before it becomes visible that can be reached by
using very sensitive methods for early diagnosis of disease
3. Is early detection possible?
• An attack by pathogen generates a complex immune response in plant
resulting in production of disease-specific proteins involved in plant
defence and in limiting the spread of infection
• Pathogens also produce proteins and toxins to facilitate their infection,
before disease symptoms appear.
• These molecules play vital role in the development of plant diagnostic
kits.
4. Diagnostic kits
• Means rapid method for the detection of microorganisms
• Designed to detect plant diseases early, either
by identifying the presence of the pathogen in the plant (by testing for
the presence of pathogen DNA), or
by molecules (proteins) produced by either the pathogen or the plant
during infection
5. Advantages
• Minimal processing time
• More accurate
• Some require laboratory equipment and training, other procedures can be
performed on site by a person with no special training
6. Crops for which diagnostic kits are used
• Rice
• Potatoes
• Papaya
• Tomatoes
• Banana
Also used for detecting genetically modified organisms (GMOs)
8. Nucleic acid-Based Diagnostic Kits
• Based on the ability of single stranded nucleic acids to bind to other
single stranded nucleic acids that are complementary in sequence
(referred to as homologous)
• Tool used in these diagnostic kits: Polymerase Chain Reaction (PCR)
9. PCR (Polymerase Chain Reaction)
• In vitro method of nucleic acid synthesis by which a particular
segment of DNA can be specifically replicated
• Invented by Karry Mullis(1987)
• PCR is an ingenious new tool for molecular biology for identification
of plant pathogens
10. Principle of PCR
• The double stranded DNA of interest is denatured to separate into two
individual strands each strand is then allowed to hybridize with a
primer (renaturation). The primer template duplex is used for DNA
synthesis (the enzyme DNA polymerase)
• These three steps denaturation, renaturation and synthesis are repeated
again and again to generate multiple forms of target DNA
11.
12. Real time PCR
• Real-time PCR (RT PCR) follows the general principle of polymerase chain
reaction
• Key feature -: amplified DNA is quantified, using fluorescent dyes, as it
accumulates in the reaction mixture after each cycle.
• Offers several advantages over normal PCR, including:
Reduced risk of sample contamination
Provision of data in real time and simultaneous testing for multiple pathogens.
Rapid on site detection
Require fewer reagents
• Real-time PCR protocols are among the most rapid species-specific detection
techniques currently available.
13. • Technique consists of two parts:
1) The synthesis of cDNA (complementary DNA) from RNA
by reverse transcription (RT)
2) The amplification of a specific cDNA by PCR
16. DNA Microarray
• Microarrays are generally composed of thousands of specific probes
spotted onto a solid surface (usually nylon or glass)
• Each probe is complementary to a specific DNA sequence (genes,
ribosomal DNA) and hybridisation with the labelled complementary
sequence provides a signal that can be detected and analysed
• Nanochip are type of microarray
• Based on an electronically addressable electrode array that provides
direct electric field control over the transport of charged molecules to
selected micro locations and concentration over an immobilized
substrate
17. • DNA microarrays are also of great use for simultaneous pathogen
detection
• Important, as plants are often infected with several pathogens forming
disease complex
• Consist of pathogen-specific DNA sequences immobilized onto a solid
surface
• Sample DNA is amplified by PCR, labeled with fluorescent dyes, and
then hybridized to the array
19. Diseases for which PCR KITS have been
developed
• Black Sigatoka disease (Mycosphaerella musicola) in bananas
• Late blight (Phytophthora infestans) in potatoes
• Fusarium wilt (Fusarium oxysporum f. sp. Vasinfectum) in cotton
20. Advantages over other
• Very sensitive compared to other techniques; detection of a small
amount of DNA is possible
• Help to detect the presence of pathogens that have long latent periods
between infection and symptom development
• Can quantify pathogen biomass in host tissue and environmental
samples, and at the same time detect fungicide resistance
• Primers in PCR diagnostic kits are very specific for the genes of a
pathogen, and amplification will occur only in diseased plants
22. Disadvantages over other
• Expensive compared to protein-based diagnostic methods
• Requires costly equipment's
• False positive results due to contamination from operator,
residual matter in testing utensils or air contamination can
result in false positive reaction
23. Protein-Based Diagnostic Kits
• First step in a defence response reaction is recognition of an invader
by a host’s immune system
• This recognition is due to the ability of specific host proteins, called
antibodies, to recognize and bind proteins that are unique to a
pathogen (antigens) and to trigger an immune reaction
24. • Protein-based diagnostic kits contain an
antibody (the primary antibody) that
can either recognize a protein from
either the pathogen or the diseased
plant.
• Because the antibody-antigen complex
cannot be seen by the naked eye,
diagnostic kits also contain a secondary
antibody, which is joined to an enzyme.
• Enzyme will catalyze a chemical
reaction that will result in a colour
change only when the primary antibody
is bound to the antigen.
• Therefore, if a color change occurs in
the kit’s reaction mixture, then the plant
pathogen is present,
25. • Enzyme-linked
immunosorbent assay
(ELISA) method makes use of
this detection system, and
forms the basis of some
protein-based diagnostic kits.
• ELISA kits are very easy to
use because test takes only a
few minutes to perform, and
does not require sophisticated
laboratory equipment or
training
26. ELISA
• Enzyme-linked immunosorbent assay
• First described by Engvall and Perlmann in 1971
• Uses a solid-phase type of enzyme immunoassay (EIA) to detect the
presence of a protein in a liquid sample using antibodies directed against the
protein to be measured
• Process:
Antigens from the sample to be tested are attached to a surface.
Then, a matching antibody is applied over the surface so it can bind the
antigen.
This antibody is linked to an enzyme and then any unbound antibodies are
removed.
In the final step, a substance containing the enzyme's substrate is added
If there was binding the subsequent reaction produces a detectable signal,
most commonly a colour change
28. • First ELISA kit developed to diagnose plant disease was by the
International Potato Center (CIP) to detect the presence of all races,
biovars, and serotypes of Ralstonia solanacearum (bacterial wilt or
brown rot in potato). Their other kits:
• sweet potato viruses: SPFMV (sweet potato feathery mottle virus),
SPCSV (sweet potato chlorotic stunt crinivirus), SPMSV (Sweet
potato mild speckling virus), SPMMV (Sweet potato mild mottle
virus), SwPLV (Sweet potato latent virus), SPCFV (Sweet
potatochlorotic fleck virus), SPCaLV (Sweet potato caulimovirus), and
C-6 (new flexuous rod virus)
32. Future perspectives
• Diagnostic kits are an investment: they may be expensive, but the costs can
be offset by gains, such as reduced crop losses and more environment-
friendly crop-management practices
• Their development should be made a priority by both the public and private
sectors in developing countries
• Genetic Engineering Services Unit of Egypt’s Agricultural Genetic
Engineering Research Institute has developed diagnostic kits and testing
services to detect viruses in crop plants.