This document provides an overview of biological mass spectrometry techniques. It discusses matrix assisted laser desorption/ionization (MALDI) and electrospray ionization (ESI) as two common ionization sources. It also describes different mass analyzer types including time-of-flight (TOF), quadrupoles, and Fourier transform ion cyclotron resonance (FT-ICR). Additionally, it covers fragmentation methods and applications of mass spectrometry in protein identification, modification analysis, and bacteria identification.
This document discusses matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). It explains that MALDI-TOF MS uses a laser to ionize biomolecules that have been mixed with an energy-absorbing matrix, and then measures the time it takes for the ions to travel through a flight tube to determine their mass-to-charge ratios. Common applications include identifying proteins, bacteria, and other microbes. The document also outlines the key components and steps of MALDI-TOF MS, including ionization, mass selection in the time-of-flight tube, and detection.
MALDI-TOF is a soft ionization technique used in mass spectrometry to analyze biomolecules such as proteins, peptides, DNA, and sugars. It works by mixing the sample with a matrix and using a laser to ionize the mixed analytes. Franz Hillenkamp and Michael Karas coined the term MALDI in 1985 after finding amino acid alanine could be easily ionized using tryptophan as a matrix. MALDI-TOF is commonly used for protein and peptide mass fingerprinting in proteomics and microbial identification in clinical and microbiological applications. It provides sensitive, high-throughput, and accurate analysis of biomolecules.
MALDI-TOF is a soft ionization technique used in mass spectrometry that allows analysis of biomolecules like proteins and polymers. It works by incorporating analyte samples into a suitable matrix that is crystallized with the analyte. A pulsed laser is used to generate ions from the sample/matrix mixture. The ions are then accelerated into a flight tube and their time of flight to a detector is used to determine mass-to-charge ratios. MALDI-TOF provides soft ionization, a broad mass range, and fast, sensitive analysis of intact biomolecules.
Mass spectrometry is an analytical technique that ionizes samples and measures the mass-to-charge ratio of ions to determine molecular masses. It requires charged gaseous molecules for analysis. Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry uses a laser to ionize analyte molecules embedded in a matrix, which are then accelerated through a flight tube based on their mass-to-charge ratios. MALDI-TOF is commonly used to analyze biomolecules like proteins and is applied in fields like proteomics, metabolomics, environmental analysis, and forensics.
MALDI is a soft ionization technique that allows analysis of biomolecules like proteins and polymers. It involves using a laser to ionize high molecular weight samples embedded in a matrix. The mechanism may involve the matrix absorbing laser energy and transferring it to the analyte, ionizing it into the gas phase. MALDI is commonly used with time of flight mass spectrometry and has applications in detecting polymers, peptides, proteins, oligonucleotides, lipids and more. It allows detection limits of femtomole to attomole levels with relative reproducibility.
Presentation on the basic Maldi-Imaging workflow with some information on how...Diane Hatziioanou
Presentation on the basic Maldi-Imaging workflow with some information on how it works. This presentation was prepared for a group meeting and is focused almost entirely on the process of MALDI-Imaging to give the group leaders an understanding of the process as well as some important information on how to make it work well.
This document discusses tandem mass spectrometry techniques. It describes two types of tandem MS: tandem-in-space, where separation elements are physically separated and tandem-in-time where separation is accomplished over time within a single instrument. It also outlines four main scan experiments - precursor ion scan, product ion scan, selected reaction monitoring, and neutral loss scan. Fragmentation techniques discussed include in-source fragmentation, post-source fragmentation using collision-induced dissociation, and notation for indicating peptide fragments.
This document discusses matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). It explains that MALDI-TOF MS uses a laser to ionize biomolecules that have been mixed with an energy-absorbing matrix, and then measures the time it takes for the ions to travel through a flight tube to determine their mass-to-charge ratios. Common applications include identifying proteins, bacteria, and other microbes. The document also outlines the key components and steps of MALDI-TOF MS, including ionization, mass selection in the time-of-flight tube, and detection.
MALDI-TOF is a soft ionization technique used in mass spectrometry to analyze biomolecules such as proteins, peptides, DNA, and sugars. It works by mixing the sample with a matrix and using a laser to ionize the mixed analytes. Franz Hillenkamp and Michael Karas coined the term MALDI in 1985 after finding amino acid alanine could be easily ionized using tryptophan as a matrix. MALDI-TOF is commonly used for protein and peptide mass fingerprinting in proteomics and microbial identification in clinical and microbiological applications. It provides sensitive, high-throughput, and accurate analysis of biomolecules.
MALDI-TOF is a soft ionization technique used in mass spectrometry that allows analysis of biomolecules like proteins and polymers. It works by incorporating analyte samples into a suitable matrix that is crystallized with the analyte. A pulsed laser is used to generate ions from the sample/matrix mixture. The ions are then accelerated into a flight tube and their time of flight to a detector is used to determine mass-to-charge ratios. MALDI-TOF provides soft ionization, a broad mass range, and fast, sensitive analysis of intact biomolecules.
Mass spectrometry is an analytical technique that ionizes samples and measures the mass-to-charge ratio of ions to determine molecular masses. It requires charged gaseous molecules for analysis. Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry uses a laser to ionize analyte molecules embedded in a matrix, which are then accelerated through a flight tube based on their mass-to-charge ratios. MALDI-TOF is commonly used to analyze biomolecules like proteins and is applied in fields like proteomics, metabolomics, environmental analysis, and forensics.
MALDI is a soft ionization technique that allows analysis of biomolecules like proteins and polymers. It involves using a laser to ionize high molecular weight samples embedded in a matrix. The mechanism may involve the matrix absorbing laser energy and transferring it to the analyte, ionizing it into the gas phase. MALDI is commonly used with time of flight mass spectrometry and has applications in detecting polymers, peptides, proteins, oligonucleotides, lipids and more. It allows detection limits of femtomole to attomole levels with relative reproducibility.
Presentation on the basic Maldi-Imaging workflow with some information on how...Diane Hatziioanou
Presentation on the basic Maldi-Imaging workflow with some information on how it works. This presentation was prepared for a group meeting and is focused almost entirely on the process of MALDI-Imaging to give the group leaders an understanding of the process as well as some important information on how to make it work well.
This document discusses tandem mass spectrometry techniques. It describes two types of tandem MS: tandem-in-space, where separation elements are physically separated and tandem-in-time where separation is accomplished over time within a single instrument. It also outlines four main scan experiments - precursor ion scan, product ion scan, selected reaction monitoring, and neutral loss scan. Fragmentation techniques discussed include in-source fragmentation, post-source fragmentation using collision-induced dissociation, and notation for indicating peptide fragments.
MALDI-TOF is a soft ionization technique that allows analysis of biomolecules like proteins and DNA. It works by using a laser to trigger desorption of analyte molecules that have been coated with an absorbing matrix, ionizing the molecules for analysis by mass spectrometry. The matrix facilitates the ionization process and protects the fragile biomolecules. MALDI is commonly paired with time-of-flight mass spectrometry due to TOF-MS's ability to analyze a wide range of molecular masses produced through the MALDI ionization process.
MALDI-TOF is a soft ionization technique used in mass spectrometry to analyze biomolecules like proteins, peptides, and sugars. It works by embedding analyte molecules in a crystalline matrix and using a laser to ionize the mixture, after which the ions are accelerated into a flight tube based on their mass-to-charge ratio. The time it takes ions to reach a detector is used to determine the mass of each analyte. Key advantages are its ability to analyze intact biomolecules, broad mass range, simple operation, and high sensitivity and resolution.
MALDI-TOF: Pricinple and Its Application in Biochemistry and BiotechnologyDevakumar Jain
The document discusses MALDI-TOF (matrix-assisted laser desorption/ionization time-of-flight) mass spectrometry. It provides a history of the development of mass spectrometry techniques. MALDI-TOF allows for the analysis of intact biomolecules like proteins and is a soft ionization method. It provides high sensitivity and mass accuracy for analyzing proteins, peptides, and other large biomolecules. The document also discusses applications of MALDI-TOF like protein identification and characterization.
MALDI-TOF mass spectrometry is a soft ionization technique used to analyze biomolecules like proteins, peptides, and polymers. It works by mixing the sample with an organic matrix and applying it to a metal plate. A pulsed laser is used to desorb the sample-matrix mixture, ionizing the analyte via proton transfer. The ions are then analyzed by a time-of-flight mass spectrometer, which measures the time it takes ions to reach the detector based on their mass-to-charge ratio. MALDI-TOF MS has applications in fields like proteomics, microbiology, and pharmaceutical analysis by providing identification and quantification of proteins, metabolites, and microorganisms.
MALDI-TOF mass spectrometry is a technique used to analyze proteins. It works by ionizing protein samples using a laser and then measuring the time it takes for the ions to travel through a flight tube, which allows calculating the mass-to-charge ratio. The sample is mixed with an absorbing matrix and dried on a target plate before being ionized by a laser pulse. Ions are accelerated through a flight tube and reach a detector, with lighter ions traveling faster and reaching it first. The time of flight is converted to a mass spectrum, allowing identification of proteins in the sample. MALDI-TOF provides sensitive, high-throughput protein analysis and is widely used in fields like proteomics, microbiology,
The document provides an overview of mass spectrometry, including its basic principles, components, working principle, and various applications. Mass spectrometry involves ionizing chemical compounds and separating the resulting ions based on their mass-to-charge ratio, producing a mass spectrum that can be used to determine the elemental or isotopic composition of a sample. Key components include an ion source, mass analyzer, and detector. Common ionization methods are also described, such as electron impact, chemical ionization, electrospray ionization, and matrix-assisted laser desorption/ionization.
Mass spectrometry (MS) measures the mass-to-charge ratio of ions to identify molecules in mixtures. MS works by ionizing samples, separating the ions by mass using electric or magnetic fields, and detecting the ions. Common applications include proteomics. Modern MS techniques like MALDI and ESI allow analyzing large biomolecules like proteins by producing intact molecular ions. Time-of-flight, quadrupoles, and orbitraps are commonly used to separate ions by mass. MS provides sensitive, specific detection down to attomole levels and has become an important analytical tool across many fields.
Tandem mass spectrometry is a technique that uses two or more mass spectrometers coupled together to analyze chemical samples. There are two types - tandem in time and tandem in space. Tandem in time uses one instrument to select an ion for fragmentation and then analyze the daughter ions. Tandem in space uses separate instruments where the first selects an ion for fragmentation in the interaction cell, and the second analyzes the product ions. Common fragmentation techniques include collision induced dissociation, electron capture dissociation, and photodissociation. Tandem MS can be used to obtain product ion spectra to identify compounds or perform selected reaction monitoring for quantitative analysis.
Proteomics 2 d gel, mass spectrometry, maldi tofnirvarna gr
This document discusses proteomics techniques including 2D gel electrophoresis and mass spectrometry. It provides an overview of 2D gel electrophoresis, describing the key steps of sample preparation, running the first and second dimensions, visualizing and analyzing the results. Mass spectrometry techniques for proteomics including MALDI-TOF and electrospray ionization are also summarized. The document outlines several applications of these proteomics approaches such as protein identification, characterization of post-translational modifications, and organism identification.
Mass Spectrometry: Protein Identification StrategiesMichel Dumontier
The document discusses protein identification strategies using mass spectrometry, including peptide mass fingerprinting (PMF) and tandem mass spectrometry. PMF involves comparing observed peptide masses from an unknown protein to theoretical masses in a database to identify matches, while tandem mass spectrometry fragments peptides and matches the fragmentation pattern to sequences in the database. The document provides details on how each technique works and their relative advantages and limitations.
Mass spectrometry is a technique that ionizes chemical compounds and sorts the ions based on their mass-to-charge ratio. It can be used to determine molecular weights, identify organic and inorganic compounds, and analyze complex mixtures. The key components of a mass spectrometer are an ion source that ionizes samples, a mass analyzer that separates the ions by mass, and a detector that records the results as a mass spectrum. Common applications of mass spectrometry include molecular structure determination, quantitative analysis of mixtures, and identification of unknown compounds.
The document describes liquid chromatography-mass spectrometry (LC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). LC-MS involves using liquid chromatography for physical separation and mass spectrometry for mass analysis to identify a variety of compounds with high sensitivity and specificity. LC-MS/MS uses tandem mass spectrometry where precursor ions from the first mass analysis (MS1) undergo fragmentation and are then analyzed in the second mass analysis (MS2) to provide additional structural information. The document discusses the components, ionization techniques, analyzers, fragmentation processes, and applications of LC-MS and LC-MS/MS.
The document discusses Ion Torrent semiconductor sequencing. It begins by providing background on first and next generation sequencing. It then describes Ion Torrent sequencing, noting that it detects pH changes from nucleotide incorporation rather than using modified nucleotides or optics. The principle, procedure involving fragmentation, ligation, amplification and pH detection on a CMOS chip, applications in genetics and medicine, advantages of speed and lower cost, and challenges including high cost per nucleotide and analysis complexity are summarized.
mass spectrometry, also called mass spectroscopy, analytic technique by which chemical substances are identified by the sorting of gaseous ions in electric and magnetic fields according to their mass-to-charge ratios.
The document discusses matrix effects, which occur when components in biological samples interfere with the ionization process during mass spectrometry analysis, potentially enhancing or suppressing the signal of the analyte. Matrix effects can negatively impact accuracy, precision, and detection limits. Two types of matrix effects are described - qualitative effects seen through post-column infusion experiments and quantitative effects evaluated by measuring the matrix factor. Approaches to minimize matrix effects include optimizing extraction and chromatography procedures, using stable isotope internal standards, and selecting an APCI ionization source instead of ESI when possible.
Localising Charged Particles by Electric and Magnetic Fields
the trapping of charged particles
Prepared By : Mohamed Fayed Mohamed Ali
Email : M10513fayed@gmail.com
Mass spectrometry is a technique that uses high energy electrons to break molecules into fragments. It then measures the masses of the fragments to reveal information about the molecular structure. Key aspects of mass spectrometry include the ionization source, mass analyzer, and detector. Common ionization methods are electron impact, electrospray, and MALDI, with softer methods like electrospray and MALDI used for larger molecules like proteins. Mass analyzers separate the ions by mass to charge ratio and include quadrupoles, time-of-flight, and magnetic sectors. The detector then counts the ions to produce a mass spectrum.
MALDI-TOF is a soft ionization technique that allows analysis of biomolecules like proteins and DNA. It works by using a laser to trigger desorption of analyte molecules that have been coated with an absorbing matrix, ionizing the molecules for analysis by mass spectrometry. The matrix facilitates the ionization process and protects the fragile biomolecules. MALDI is commonly paired with time-of-flight mass spectrometry due to TOF-MS's ability to analyze a wide range of molecular masses produced through the MALDI ionization process.
MALDI-TOF is a soft ionization technique used in mass spectrometry to analyze biomolecules like proteins, peptides, and sugars. It works by embedding analyte molecules in a crystalline matrix and using a laser to ionize the mixture, after which the ions are accelerated into a flight tube based on their mass-to-charge ratio. The time it takes ions to reach a detector is used to determine the mass of each analyte. Key advantages are its ability to analyze intact biomolecules, broad mass range, simple operation, and high sensitivity and resolution.
MALDI-TOF: Pricinple and Its Application in Biochemistry and BiotechnologyDevakumar Jain
The document discusses MALDI-TOF (matrix-assisted laser desorption/ionization time-of-flight) mass spectrometry. It provides a history of the development of mass spectrometry techniques. MALDI-TOF allows for the analysis of intact biomolecules like proteins and is a soft ionization method. It provides high sensitivity and mass accuracy for analyzing proteins, peptides, and other large biomolecules. The document also discusses applications of MALDI-TOF like protein identification and characterization.
MALDI-TOF mass spectrometry is a soft ionization technique used to analyze biomolecules like proteins, peptides, and polymers. It works by mixing the sample with an organic matrix and applying it to a metal plate. A pulsed laser is used to desorb the sample-matrix mixture, ionizing the analyte via proton transfer. The ions are then analyzed by a time-of-flight mass spectrometer, which measures the time it takes ions to reach the detector based on their mass-to-charge ratio. MALDI-TOF MS has applications in fields like proteomics, microbiology, and pharmaceutical analysis by providing identification and quantification of proteins, metabolites, and microorganisms.
MALDI-TOF mass spectrometry is a technique used to analyze proteins. It works by ionizing protein samples using a laser and then measuring the time it takes for the ions to travel through a flight tube, which allows calculating the mass-to-charge ratio. The sample is mixed with an absorbing matrix and dried on a target plate before being ionized by a laser pulse. Ions are accelerated through a flight tube and reach a detector, with lighter ions traveling faster and reaching it first. The time of flight is converted to a mass spectrum, allowing identification of proteins in the sample. MALDI-TOF provides sensitive, high-throughput protein analysis and is widely used in fields like proteomics, microbiology,
The document provides an overview of mass spectrometry, including its basic principles, components, working principle, and various applications. Mass spectrometry involves ionizing chemical compounds and separating the resulting ions based on their mass-to-charge ratio, producing a mass spectrum that can be used to determine the elemental or isotopic composition of a sample. Key components include an ion source, mass analyzer, and detector. Common ionization methods are also described, such as electron impact, chemical ionization, electrospray ionization, and matrix-assisted laser desorption/ionization.
Mass spectrometry (MS) measures the mass-to-charge ratio of ions to identify molecules in mixtures. MS works by ionizing samples, separating the ions by mass using electric or magnetic fields, and detecting the ions. Common applications include proteomics. Modern MS techniques like MALDI and ESI allow analyzing large biomolecules like proteins by producing intact molecular ions. Time-of-flight, quadrupoles, and orbitraps are commonly used to separate ions by mass. MS provides sensitive, specific detection down to attomole levels and has become an important analytical tool across many fields.
Tandem mass spectrometry is a technique that uses two or more mass spectrometers coupled together to analyze chemical samples. There are two types - tandem in time and tandem in space. Tandem in time uses one instrument to select an ion for fragmentation and then analyze the daughter ions. Tandem in space uses separate instruments where the first selects an ion for fragmentation in the interaction cell, and the second analyzes the product ions. Common fragmentation techniques include collision induced dissociation, electron capture dissociation, and photodissociation. Tandem MS can be used to obtain product ion spectra to identify compounds or perform selected reaction monitoring for quantitative analysis.
Proteomics 2 d gel, mass spectrometry, maldi tofnirvarna gr
This document discusses proteomics techniques including 2D gel electrophoresis and mass spectrometry. It provides an overview of 2D gel electrophoresis, describing the key steps of sample preparation, running the first and second dimensions, visualizing and analyzing the results. Mass spectrometry techniques for proteomics including MALDI-TOF and electrospray ionization are also summarized. The document outlines several applications of these proteomics approaches such as protein identification, characterization of post-translational modifications, and organism identification.
Mass Spectrometry: Protein Identification StrategiesMichel Dumontier
The document discusses protein identification strategies using mass spectrometry, including peptide mass fingerprinting (PMF) and tandem mass spectrometry. PMF involves comparing observed peptide masses from an unknown protein to theoretical masses in a database to identify matches, while tandem mass spectrometry fragments peptides and matches the fragmentation pattern to sequences in the database. The document provides details on how each technique works and their relative advantages and limitations.
Mass spectrometry is a technique that ionizes chemical compounds and sorts the ions based on their mass-to-charge ratio. It can be used to determine molecular weights, identify organic and inorganic compounds, and analyze complex mixtures. The key components of a mass spectrometer are an ion source that ionizes samples, a mass analyzer that separates the ions by mass, and a detector that records the results as a mass spectrum. Common applications of mass spectrometry include molecular structure determination, quantitative analysis of mixtures, and identification of unknown compounds.
The document describes liquid chromatography-mass spectrometry (LC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). LC-MS involves using liquid chromatography for physical separation and mass spectrometry for mass analysis to identify a variety of compounds with high sensitivity and specificity. LC-MS/MS uses tandem mass spectrometry where precursor ions from the first mass analysis (MS1) undergo fragmentation and are then analyzed in the second mass analysis (MS2) to provide additional structural information. The document discusses the components, ionization techniques, analyzers, fragmentation processes, and applications of LC-MS and LC-MS/MS.
The document discusses Ion Torrent semiconductor sequencing. It begins by providing background on first and next generation sequencing. It then describes Ion Torrent sequencing, noting that it detects pH changes from nucleotide incorporation rather than using modified nucleotides or optics. The principle, procedure involving fragmentation, ligation, amplification and pH detection on a CMOS chip, applications in genetics and medicine, advantages of speed and lower cost, and challenges including high cost per nucleotide and analysis complexity are summarized.
mass spectrometry, also called mass spectroscopy, analytic technique by which chemical substances are identified by the sorting of gaseous ions in electric and magnetic fields according to their mass-to-charge ratios.
The document discusses matrix effects, which occur when components in biological samples interfere with the ionization process during mass spectrometry analysis, potentially enhancing or suppressing the signal of the analyte. Matrix effects can negatively impact accuracy, precision, and detection limits. Two types of matrix effects are described - qualitative effects seen through post-column infusion experiments and quantitative effects evaluated by measuring the matrix factor. Approaches to minimize matrix effects include optimizing extraction and chromatography procedures, using stable isotope internal standards, and selecting an APCI ionization source instead of ESI when possible.
Localising Charged Particles by Electric and Magnetic Fields
the trapping of charged particles
Prepared By : Mohamed Fayed Mohamed Ali
Email : M10513fayed@gmail.com
Mass spectrometry is a technique that uses high energy electrons to break molecules into fragments. It then measures the masses of the fragments to reveal information about the molecular structure. Key aspects of mass spectrometry include the ionization source, mass analyzer, and detector. Common ionization methods are electron impact, electrospray, and MALDI, with softer methods like electrospray and MALDI used for larger molecules like proteins. Mass analyzers separate the ions by mass to charge ratio and include quadrupoles, time-of-flight, and magnetic sectors. The detector then counts the ions to produce a mass spectrum.
This document provides an overview of LC/MS/MS technology and applications. It discusses the advantages of LC/MS/MS over other techniques, describes various ionization methods with a focus on electrospray ionization, and explains the process of tandem mass spectrometry using triple quadrupole and ion trap instruments. The document also reviews instrumental parameters and common MS/MS modes such as MRM and product ion scanning.
This document provides an overview of LC/MS/MS technology, focusing on electrospray ionization and triple quadrupole mass spectrometers. It discusses the advantages of LC/MS/MS over other techniques, the process of electrospray ionization, and how triple quadrupole and ion trap mass analyzers work. Specifically, it explains how electrospray produces gas phase ions, the function of each quadrupole in triple quadrupole instruments, and the differences between triple quadrupoles and ion traps in terms of sensitivity, mass resolution, and fragmentation capabilities.
This document provides an overview of magnetic resonance imaging (MRI) including:
1. The history and timeline of MRI development from the 1920s to present day. Key developments include the discoveries of nuclear magnetic resonance and techniques for generating MRI images using gradients.
2. The basic components and principles of how MRI works including strong magnets, gradient coils, radiofrequency coils, spin precession, relaxation times, and Fourier transforms to generate images.
3. Explanations of fundamental MRI sequences including T1-weighted, T2-weighted images and how contrast is achieved using repetition time and echo time.
4. Clinical applications of MRI including its advantages over other imaging modalities as well as some disadvantages and
Infrared spectroscopy is a technique that uses infrared light to determine the functional groups present in molecules based on the vibrations of atoms. It works by passing infrared radiation through a sample and measuring the absorption of specific wavelengths, which correspond to vibrations between bonds of different atoms. The peaks in an infrared spectrum can identify functional groups and chemical bonds based on the wavelength of absorption. Fourier transform infrared spectroscopy is now commonly used as it allows simultaneous detection of all infrared wavelengths for faster analysis.
A tandem mass spectrometry (TANDEM MS), also named as MS/MS, is a two-step technique used to analyze a sample either by using two or more mass spectrometers connected to each other or a single mass spectrometer by several analyzers arranged one after another.
Mass spectrometry works by ionizing molecule samples and then sorting the resulting ions based on their mass-to-charge ratio. Samples are bombarded with electrons which causes ionization, and the ions are then accelerated and deflected according to their mass. This provides information about molecular weights, elemental compositions, and structural characteristics that can be used to identify unknown compounds. Common ionization methods include electron impact, chemical ionization, and matrix-assisted laser desorption/ionization. Ions are typically analyzed using quadrupole mass filters or magnetic sectors before being detected.
1) The document discusses various types of neutron detectors, their detection principles, energy response characteristics, and challenges in accurately measuring neutron dose equivalent rates. It focuses on REM balls but also covers other technologies like TEPC, mixed gas detectors, and CLYC.
2) Key points covered include how detector response varies with neutron energy spectrum, factors of over or under response depending on energy, and importance of characterizing the neutron field energy spectrum. It also highlights challenges in accounting for directionality and mixed gamma/neutron exposures.
3) Newer portable neutron detectors like mixed gas, Domino, and CLYC provide alternatives to REM balls and aim to improve gamma rejection, energy response, and form factor for radiological
This document provides an overview of nuclear magnetic resonance (NMR) spectroscopy and its applications to determining organic compound structures. It discusses key aspects of NMR spectroscopy including the physical principles, experimental setup, and characteristics of spin 1/2 nuclei commonly studied like protons, carbon-13, fluorine-19, and phosphorus-31. It also describes proton NMR spectroscopy specifically and how it is used to analyze sample solutions in deuterated solvents and determine chemical shifts.
Nuclear magnetic resonance (NMR) spectroscopy uses radio waves to analyze atomic nuclei and determine molecular structure. NMR instruments apply a strong magnetic field to align atomic nuclei, then apply a radiofrequency pulse to excite the nuclei. As the nuclei relax back to equilibrium, they emit radiofrequency signals that are measured. Fourier transform NMR analyzes these signals in the time domain to produce a frequency domain spectrum that reveals details of molecular structure. Modern high-field NMR spectrometers use superconducting magnets producing fields over 20 Tesla to achieve high resolution.
A laser is a device that emits coherent light through stimulated emission of photons. It works by pumping a gain medium with an external energy source to produce a population inversion between quantum energy states. Photons are emitted through stimulated emission, resulting in a collimated beam of light that is monochromatic, coherent, and highly directional. Common laser types include solid-state, liquid, gas, excimer, and semiconductor lasers, which use different gain media and pumping mechanisms but operate on similar principles of stimulated emission and optical feedback in a resonant cavity. Lasers have applications in science, industry, medicine, communications, and defense.
Mass spectrometry is an analytical technique that produces spectra of molecules by ionizing samples and measuring their mass-to-charge ratios. There are various ionization techniques used in mass spectrometry including electron impact ionization, fast atom bombardment, electrospray ionization, chemical ionization, and matrix-assisted laser desorption/ionization. These techniques can be "hard" and cause extensive fragmentation or "soft" and produce little fragmentation. The choice of ionization technique depends on the type of compounds being analyzed.
The document discusses array detectors used in spectroscopy. It describes photodiode array detectors and charged coupled device (CCD) detectors. Photodiode array detectors contain an array of silicon photodiodes on a single chip that can simultaneously measure radiation intensities at all wavelengths. CCD detectors contain an array of linked capacitors that can transfer electric charges between neighboring capacitors, allowing detection of low intensity light signals. Both detector types offer advantages like low noise, wide spectral response, and simultaneous detection of emissions at different wavelengths.
The document summarizes a coarse-grained molecular dynamics simulation of DNA translocation through a nanopore. Two nanopore systems were modeled (System A and B) with different pore geometries and sizes. Snapshots from the simulations showed DNA conformations outside, during capture, and inside the pore. Plots of the DNA center of mass over time demonstrated capture and translocation. The simulations provided insight into how DNA bending and stretching occurs during translocation and how pore size and shape can influence the process.
SIMS is a technique that uses a focused primary ion beam to bombard a sample surface, emitting secondary ions that are then analyzed using mass spectrometry. It allows for highly sensitive elemental and isotopic analysis of surfaces down to parts-per-billion. SIMS can be used in either static or dynamic mode to obtain spatial or depth profiles of sample composition. While very sensitive, it is also an expensive technique. Common applications include detecting trace impurities in semiconductors and generating high-resolution maps of elemental distributions.
IR spectroscopy analyzes infrared light interacting with molecules to determine their structure based on their vibrational and rotational absorption spectra. IR light is passed through a sample and the absorbed wavelengths are measured to produce a spectrum that can identify functional groups and molecular structures. Key components of IR instruments include IR light sources, monochromators to select wavelengths, detectors to measure absorption, and displays to present spectra for analysis. IR spectroscopy has applications in qualitative analysis, industrial quality control, and examining artifacts.
Analytical Spectroscopic systems
Mass Spectrometry
Atomic mass to charge ratio
Laser Raman
Spectroscopy
Molecular vibrational modes
Laser Induced
Breakdown
Spectroscopy
Atomic emission
Visible Reflectance
Spectroscopy
Reflected color
Building RAG with self-deployed Milvus vector database and Snowpark Container...Zilliz
This talk will give hands-on advice on building RAG applications with an open-source Milvus database deployed as a docker container. We will also introduce the integration of Milvus with Snowpark Container Services.
For the full video of this presentation, please visit: https://www.edge-ai-vision.com/2024/06/building-and-scaling-ai-applications-with-the-nx-ai-manager-a-presentation-from-network-optix/
Robin van Emden, Senior Director of Data Science at Network Optix, presents the “Building and Scaling AI Applications with the Nx AI Manager,” tutorial at the May 2024 Embedded Vision Summit.
In this presentation, van Emden covers the basics of scaling edge AI solutions using the Nx tool kit. He emphasizes the process of developing AI models and deploying them globally. He also showcases the conversion of AI models and the creation of effective edge AI pipelines, with a focus on pre-processing, model conversion, selecting the appropriate inference engine for the target hardware and post-processing.
van Emden shows how Nx can simplify the developer’s life and facilitate a rapid transition from concept to production-ready applications.He provides valuable insights into developing scalable and efficient edge AI solutions, with a strong focus on practical implementation.
TrustArc Webinar - 2024 Global Privacy SurveyTrustArc
How does your privacy program stack up against your peers? What challenges are privacy teams tackling and prioritizing in 2024?
In the fifth annual Global Privacy Benchmarks Survey, we asked over 1,800 global privacy professionals and business executives to share their perspectives on the current state of privacy inside and outside of their organizations. This year’s report focused on emerging areas of importance for privacy and compliance professionals, including considerations and implications of Artificial Intelligence (AI) technologies, building brand trust, and different approaches for achieving higher privacy competence scores.
See how organizational priorities and strategic approaches to data security and privacy are evolving around the globe.
This webinar will review:
- The top 10 privacy insights from the fifth annual Global Privacy Benchmarks Survey
- The top challenges for privacy leaders, practitioners, and organizations in 2024
- Key themes to consider in developing and maintaining your privacy program
UiPath Test Automation using UiPath Test Suite series, part 6DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 6. In this session, we will cover Test Automation with generative AI and Open AI.
UiPath Test Automation with generative AI and Open AI webinar offers an in-depth exploration of leveraging cutting-edge technologies for test automation within the UiPath platform. Attendees will delve into the integration of generative AI, a test automation solution, with Open AI advanced natural language processing capabilities.
Throughout the session, participants will discover how this synergy empowers testers to automate repetitive tasks, enhance testing accuracy, and expedite the software testing life cycle. Topics covered include the seamless integration process, practical use cases, and the benefits of harnessing AI-driven automation for UiPath testing initiatives. By attending this webinar, testers, and automation professionals can gain valuable insights into harnessing the power of AI to optimize their test automation workflows within the UiPath ecosystem, ultimately driving efficiency and quality in software development processes.
What will you get from this session?
1. Insights into integrating generative AI.
2. Understanding how this integration enhances test automation within the UiPath platform
3. Practical demonstrations
4. Exploration of real-world use cases illustrating the benefits of AI-driven test automation for UiPath
Topics covered:
What is generative AI
Test Automation with generative AI and Open AI.
UiPath integration with generative AI
Speaker:
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
GraphSummit Singapore | The Art of the Possible with Graph - Q2 2024Neo4j
Neha Bajwa, Vice President of Product Marketing, Neo4j
Join us as we explore breakthrough innovations enabled by interconnected data and AI. Discover firsthand how organizations use relationships in data to uncover contextual insights and solve our most pressing challenges – from optimizing supply chains, detecting fraud, and improving customer experiences to accelerating drug discoveries.
Why You Should Replace Windows 11 with Nitrux Linux 3.5.0 for enhanced perfor...SOFTTECHHUB
The choice of an operating system plays a pivotal role in shaping our computing experience. For decades, Microsoft's Windows has dominated the market, offering a familiar and widely adopted platform for personal and professional use. However, as technological advancements continue to push the boundaries of innovation, alternative operating systems have emerged, challenging the status quo and offering users a fresh perspective on computing.
One such alternative that has garnered significant attention and acclaim is Nitrux Linux 3.5.0, a sleek, powerful, and user-friendly Linux distribution that promises to redefine the way we interact with our devices. With its focus on performance, security, and customization, Nitrux Linux presents a compelling case for those seeking to break free from the constraints of proprietary software and embrace the freedom and flexibility of open-source computing.
Goodbye Windows 11: Make Way for Nitrux Linux 3.5.0!SOFTTECHHUB
As the digital landscape continually evolves, operating systems play a critical role in shaping user experiences and productivity. The launch of Nitrux Linux 3.5.0 marks a significant milestone, offering a robust alternative to traditional systems such as Windows 11. This article delves into the essence of Nitrux Linux 3.5.0, exploring its unique features, advantages, and how it stands as a compelling choice for both casual users and tech enthusiasts.
Enchancing adoption of Open Source Libraries. A case study on Albumentations.AIVladimir Iglovikov, Ph.D.
Presented by Vladimir Iglovikov:
- https://www.linkedin.com/in/iglovikov/
- https://x.com/viglovikov
- https://www.instagram.com/ternaus/
This presentation delves into the journey of Albumentations.ai, a highly successful open-source library for data augmentation.
Created out of a necessity for superior performance in Kaggle competitions, Albumentations has grown to become a widely used tool among data scientists and machine learning practitioners.
This case study covers various aspects, including:
People: The contributors and community that have supported Albumentations.
Metrics: The success indicators such as downloads, daily active users, GitHub stars, and financial contributions.
Challenges: The hurdles in monetizing open-source projects and measuring user engagement.
Development Practices: Best practices for creating, maintaining, and scaling open-source libraries, including code hygiene, CI/CD, and fast iteration.
Community Building: Strategies for making adoption easy, iterating quickly, and fostering a vibrant, engaged community.
Marketing: Both online and offline marketing tactics, focusing on real, impactful interactions and collaborations.
Mental Health: Maintaining balance and not feeling pressured by user demands.
Key insights include the importance of automation, making the adoption process seamless, and leveraging offline interactions for marketing. The presentation also emphasizes the need for continuous small improvements and building a friendly, inclusive community that contributes to the project's growth.
Vladimir Iglovikov brings his extensive experience as a Kaggle Grandmaster, ex-Staff ML Engineer at Lyft, sharing valuable lessons and practical advice for anyone looking to enhance the adoption of their open-source projects.
Explore more about Albumentations and join the community at:
GitHub: https://github.com/albumentations-team/albumentations
Website: https://albumentations.ai/
LinkedIn: https://www.linkedin.com/company/100504475
Twitter: https://x.com/albumentations
Alt. GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using ...James Anderson
Effective Application Security in Software Delivery lifecycle using Deployment Firewall and DBOM
The modern software delivery process (or the CI/CD process) includes many tools, distributed teams, open-source code, and cloud platforms. Constant focus on speed to release software to market, along with the traditional slow and manual security checks has caused gaps in continuous security as an important piece in the software supply chain. Today organizations feel more susceptible to external and internal cyber threats due to the vast attack surface in their applications supply chain and the lack of end-to-end governance and risk management.
The software team must secure its software delivery process to avoid vulnerability and security breaches. This needs to be achieved with existing tool chains and without extensive rework of the delivery processes. This talk will present strategies and techniques for providing visibility into the true risk of the existing vulnerabilities, preventing the introduction of security issues in the software, resolving vulnerabilities in production environments quickly, and capturing the deployment bill of materials (DBOM).
Speakers:
Bob Boule
Robert Boule is a technology enthusiast with PASSION for technology and making things work along with a knack for helping others understand how things work. He comes with around 20 years of solution engineering experience in application security, software continuous delivery, and SaaS platforms. He is known for his dynamic presentations in CI/CD and application security integrated in software delivery lifecycle.
Gopinath Rebala
Gopinath Rebala is the CTO of OpsMx, where he has overall responsibility for the machine learning and data processing architectures for Secure Software Delivery. Gopi also has a strong connection with our customers, leading design and architecture for strategic implementations. Gopi is a frequent speaker and well-known leader in continuous delivery and integrating security into software delivery.
Sudheer Mechineni, Head of Application Frameworks, Standard Chartered Bank
Discover how Standard Chartered Bank harnessed the power of Neo4j to transform complex data access challenges into a dynamic, scalable graph database solution. This keynote will cover their journey from initial adoption to deploying a fully automated, enterprise-grade causal cluster, highlighting key strategies for modelling organisational changes and ensuring robust disaster recovery. Learn how these innovations have not only enhanced Standard Chartered Bank’s data infrastructure but also positioned them as pioneers in the banking sector’s adoption of graph technology.
GraphSummit Singapore | The Future of Agility: Supercharging Digital Transfor...Neo4j
Leonard Jayamohan, Partner & Generative AI Lead, Deloitte
This keynote will reveal how Deloitte leverages Neo4j’s graph power for groundbreaking digital twin solutions, achieving a staggering 100x performance boost. Discover the essential role knowledge graphs play in successful generative AI implementations. Plus, get an exclusive look at an innovative Neo4j + Generative AI solution Deloitte is developing in-house.
Cosa hanno in comune un mattoncino Lego e la backdoor XZ?Speck&Tech
ABSTRACT: A prima vista, un mattoncino Lego e la backdoor XZ potrebbero avere in comune il fatto di essere entrambi blocchi di costruzione, o dipendenze di progetti creativi e software. La realtà è che un mattoncino Lego e il caso della backdoor XZ hanno molto di più di tutto ciò in comune.
Partecipate alla presentazione per immergervi in una storia di interoperabilità, standard e formati aperti, per poi discutere del ruolo importante che i contributori hanno in una comunità open source sostenibile.
BIO: Sostenitrice del software libero e dei formati standard e aperti. È stata un membro attivo dei progetti Fedora e openSUSE e ha co-fondato l'Associazione LibreItalia dove è stata coinvolta in diversi eventi, migrazioni e formazione relativi a LibreOffice. In precedenza ha lavorato a migrazioni e corsi di formazione su LibreOffice per diverse amministrazioni pubbliche e privati. Da gennaio 2020 lavora in SUSE come Software Release Engineer per Uyuni e SUSE Manager e quando non segue la sua passione per i computer e per Geeko coltiva la sua curiosità per l'astronomia (da cui deriva il suo nickname deneb_alpha).
Let's Integrate MuleSoft RPA, COMPOSER, APM with AWS IDP along with Slackshyamraj55
Discover the seamless integration of RPA (Robotic Process Automation), COMPOSER, and APM with AWS IDP enhanced with Slack notifications. Explore how these technologies converge to streamline workflows, optimize performance, and ensure secure access, all while leveraging the power of AWS IDP and real-time communication via Slack notifications.
Observability Concepts EVERY Developer Should Know -- DeveloperWeek Europe.pdfPaige Cruz
Monitoring and observability aren’t traditionally found in software curriculums and many of us cobble this knowledge together from whatever vendor or ecosystem we were first introduced to and whatever is a part of your current company’s observability stack.
While the dev and ops silo continues to crumble….many organizations still relegate monitoring & observability as the purview of ops, infra and SRE teams. This is a mistake - achieving a highly observable system requires collaboration up and down the stack.
I, a former op, would like to extend an invitation to all application developers to join the observability party will share these foundational concepts to build on:
UiPath Test Automation using UiPath Test Suite series, part 5DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 5. In this session, we will cover CI/CD with devops.
Topics covered:
CI/CD with in UiPath
End-to-end overview of CI/CD pipeline with Azure devops
Speaker:
Lyndsey Byblow, Test Suite Sales Engineer @ UiPath, Inc.
2. Biological Mass Spectrometry
General Mass Spectrometry
The General mass spectrometer
Analyzers types
Calibrations and mass Accuracy
Detection
Matrix Assisted Laser Desorption (MALDI)
TOF
Electrospray Ionization (ESI)
Quadrupoles, Ion Traps, FTMS, and O-TOF
Fragmentation
Post source dissociation (PSD) (with MALDI)
In source dissociation (with ESI)
Collision induced dissociation CID
IRMPD and ESI
3. The General Mass Spectrometry
M a s s S p e c tro m e te r
Io n S o u rc e A n a ly z e r D e te c to r
M ALDI TO F
S p ra y S o u rc e s Q u a d r u p o le s
T r a p p in g in s t r u m e n t s
4. Analyzers
• Time of Flights mass spectrometer
• Quadrupole mass spectrometer
• Quadrupole Ion traps
• FT-MS, FT-ICR
5. Time-of-flight Mass
Spectrometers
• Basically a tube that ions travel through
with lower mass ions traveling quicker
through the tube.
• Reflectron increases resolution by
compensating for energy and increasing
path length.
• Delayed extraction increases resolution.
10. Calibration
• All Mass Spectrometers MUST BE CALIBRATED. This adjust
parameters in the mass assignment of the ions.
• In general, the closer in space and time the calibration is the more
accurate the calibration.
• Default calibrations are usually set up on instruments for nominal
mass accuracy.
• Calibrations can be done with any compound with a known elemental
formula. The best calibration compounds are similar type of
compounds to the type you are going to measure accurately.
• It is best to have calibration compounds above and below the
compound of interest
11. Mass Accuracy
• Higher resolution allows for higher mass accuracy
in two ways
– Resolves stardards and sample from background
– Better centroiding of peaks
• Use of internal standards with a high resolution
(>10,000) is the “Gold standard” for mass
accuracy.
• Mass Accuracy needed is dependent on use and
available information.
13. WHY MALDI?
• Less Sensitive to Salts
• Lower PRACTICAL detection limits
• Easier to interpret spectra (less multiple
charges)
• Quick and easy
• Higher mass detection
• Higher Throughput (>1000 samples per
hour)
14. Matrix
• Needs to be involatile (most are solids at
room temperature)
• Needs to absorb the laser wavelength that
you are using. (most cases 337 nm)
• Preferably dissolves in same solvent as the
sample
• Typically, the matrices are acidic.
15. HOT and Cold Matrices
• DHB is a cold matrix, the samples are not
as likely to be fragmented, may not ionize
some molecules.
• Alpha-cyano dihydroxybenzoic acid is
considered a hot matrix. More likely to
fragment the molecules. Can produce
multiply charged proteins.
16. Sample preparation
• Dried Droplet- mix sample with matrix and
drop on plate at the same time. –Easy to do.
• Layered method- put matrix on plate then
dry before adding sample. Good for low
concentrations, more difficult.
• Want high Matrix-Analyte ratio.
17. The MALDI Instrument
T im e - o f F lig h t
M a s s S p e c tro m e te r
S o u rc e A n a ly z e r D e te c to r
D e la y e d E x t r a c t io n R e fle c t r o n W h y d e fle c t t h e io n s ?
PSD
18. Basic Physics
• Kinetic Energy= ½ mv2
• Potential Energy of charged particle=qV
• Potential Energy +Kinetic Energy=Constant
19. Delayed Extraction
• Kinetic Energy of ions leaving the surface is not
constant. Also, their could be a time delay, in
addition.
• Delayed Extraction is a method used to
compensate for the spread of kinetic energy of the
ions leaving the surface.
• Delayed Extraction is mass dependent.
• Delayed Extraction will also compensate for some
time delay of ions coming off the surface.
24. T t4
=
Sam ple plate
M1 kE< M2 kE
E= kE + PE
Potential Voltage
M1 kE > M2 kE
Detector
M1
M2
25. Reflectron
• The reflectron is another method used to
compensate for the spread in Kinetic
energies in the time of flight.
• Reflectron does not compensate for any
time delay coming off the surface.
• Three types of reflectrons ( single stage,
two stage, and curved field)
31. Why Deflect the ions?
• Detector is made up of multiple detectors similar
to the electron multiplier called “channels”.
• When an ion strikes the detector the “channel” is
dead for milliseconds.
• When to many matrix ions hit the detector, it kills
the signal.
• Linear detector is specially design to compensate
for larger number of ions, but is not perfect.
32. Why Electrospray Ionization?
• Electrospray Ionization can be easily
interfaced to LC.
• Absolute signals from Electrospray are
more easily reproduced, therefore, better
quantitation.
• Mass Accuracy is considered better.
• Multiple charging is more common then
MALDI.
34. Advantages of Multiple Charging
• Can use instruments with lower maximum
m/z (i.e., Quadrupoles, ion traps, FTMS)
• For FTMS, the resolution is better at lower
m/z values, therefore, ESI helps one obtain
better resolution at higher m/z values.
• Multiply charge ions tend to fragment easier
then singly charge ions.
36. Needle options
• High flow needles (for connection to
regular LC columns(up to 1ml/min))
• Nanospray needles (high sensitivity work)
• Microspray needles (connected to micro LC
columns)
• Atmospheric Pressure Chemical Ionization
(for non-polar molecules)
• Multiple needles setups
37. Why Fragment the ions?
• Molecular weight is only one piece of data
the instrument can provide
• Data base searches on tryptic peptides do
not always reveal the protein.
• Sequence and modification information can
be obtained by fragmentation
38. Ways to Induce Fragmentation
• Post Source Decay-MALDI
• In source Dissociation-ESI
• Low Energy –High Energy Collision
induced dissociation
• Inferred multi-photon dissociation (in a
trap)
• Electron Capture dissociation (in a trap)
40. PSD
• Easily done on simple MALDI with
reflectron
• Might not produce enough fragments
• Relatively low precursor ion selection
41. Physics Reminder
• Conservation of Energy assures that the
kinetic energy of fragments is determined
by the relative masses of the products.
• KE=1/2mv2
• KEprecursor=KEproduct ion+KEproduct neutral
• vprecursor=vproduct ion
• KEproduct ion=KEprecursor*(mproduct ion/mprecursor)
44. M > M2
K > K2
1
Velocity in Field Free
Region on the same
for both fragments
45. Types of Reflectrons
• Two stage- Give best resolution on single MS
mode, requires doing PSD in Stages.
• Single Stage-Large Reflector takes a significant
amount of space. PSD can be done in single stage,
however, low mass product ions have poor
resolution.
• Curved field-Another Large Reflector that takes
up space. Allows PSD to be obtained in single
stage with good resolution throughout PSD, but
single MS mode does not have as good a
resolution.
46. In Source Dissociation
• This is done by increasing the voltage between the
entrance to the sample orifice and the first
skimmer.
• Can be done on simple electrospray instrument.
• Produces results similar to low energy CID
• No mass selection, therefore, requires sample to be
extremely pure.
• Can be used to produce multiple MS on triple and
hybrid instruments.
47. CID
• CID is divided into low energy (<100 eV) and
high energy(>1000 eV) based on the collision
energy.
• High energy CID produces more fragments, but is
more complicated to interpret.
• Low energy CID has a limit on the m/z it can
dissociate of approximately 1000.
• High energy CID produces charge remote
fragmentation that can be used to distinguish
leucine and isoleucine.
48. IRMPD and ECD
• Complimentary techniques
• Can only be performed in trapping
instruments-Mostly FTMS.
• ECD requires a multiply charged ion
• Used for dissociating high molecular weight
fragments
49. Interpretation of Tandem Mass
Spectra of Peptides
• Known Sequence- Calculate expected fragments
and compare to tandem spectra to see match
• Modified Sequence-Calculate unmodified
sequence compare to tandem spectra to see
difference where modification occurs.
• Unknown Sequence- Check Database to see if it is
a match
• Unknown Sequence not in Database- Manual
Interpretation (Practice!Practice!Practice!)
51. Manual Interpretation
• Goal-Assign as many abundant fragments as
possible to a spectra
• Remember Cysteine modifications
• Know type of fragments that are typically
observed by dissociation method.
– Low Energy (b and y, loss of neutrals from these
fragments)
– High Energy (x,y,z, a,b,c, v, d,w)
Reference: Ioannis A Papayannopoulos, Mass Spec.
Rev.,1995, vol. 14, 49-73.
52. Steps in Manual Interpretation
• Choose a large peak
• Look for ions that are different in mass from the
fragment by a specific amino acid mass. If there is
look for an other fragment that differs by a
specific amino acid mass to build a partial
sequence.
• Decide the type of fragments that corresponds to
the above sequence by either mass difference to
the precursor or complimentary fragments.
• Look for other complimentary fragments and low
mass ions to confirm the partial sequence.
• Choose another unassigned peak and repeat
procedures until sequence is determined.
53. Peptide modifications to help
Interpretation
• O18 water digestion- all C terminal
fragments will have unique Isotope pattern
• N-terminal or C-terminal modifications-
results in distinct fragmentation patterns.
54. LC Interfaces
• Direct LC with Electrospray.
– Direct connection to mass spectrometer
– Real Time monitoring
• Vacuum deposition for MALDI
– Indirect conection to mass spectrometer
– Not Real Time, allows one to make decisions
later. Multiple MS/MS on single LC peaks.
55. LC detection methods
• Simple acquiring of spectra.
• Precursor and product ion scans
• Data Dependent scans
• Selective Ion Monitoring
• Selective Reaction monitoring
56. Applications
• Protein Identifications
• Protein Modifications
• Bacteria Identifications
• SNP’s
57. Protein Identification
• Identify Protein mass
• Digest Protein
• Analyze by MALDI
• Data Base Search
• If negative results, go to Tandem Mass
Spectrometry
• Data Base Search on Tandem Mass
Spectrum
58. Protein Modifications
• Tandem Mass Spectrometry is very important
• Can obtain full mass of proteins to help determine
mass and number of modifications
• Digest proteins and run mass spectrometry.
• Use Tandem to determine the exact position
• Use of unmodified protein or peptide can be useful
in the interpretation
59. Bacteria Identification
• Uses MALDI of Bacteria to Identify
Proteins produced by bacteria
• Data base search of MALDI spectra
identifies bacteria
• At this point, no large consistent Data Base
is available.