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Mass Spectrometry: An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.
 JoVE Immunology and Infection

Rapid Identification of Gram Negative Bacteria from Blood Culture Broth Using MALDI-TOF Mass Spectrometry

1Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Medical Research, Westmead Hospital, 2Centre for Research Excellence in Critical Infection, Westmead Millennium Institute, Westmead Hospital, 3Sydney Emerging Infectious Diseases Institute, University of Sydney, Westmead Hospital


JoVE 51663

 JoVE Biology

Quantification of Proteins Using Peptide Immunoaffinity Enrichment Coupled with Mass Spectrometry

1Clinical Research Division, Fred Hutchinson Cancer Research Center - FHCRC, 2Department of Biochemistry and Microbiology, University of Victoria, 3Broad Institute of MIT and Harvard, 4Genome BC Proteomics Centre, University of Victoria, 5Plasma Proteome Institute


JoVE 2812

 Science Education: Essentials of Analytical Chemistry

Introduction to Mass Spectrometry

JoVE Science Education

Source: Laboratory of Dr. Khuloud Al-Jamal - King's College London

Mass spectrometry is an analytical chemistry technique that enables the identification of unknown compounds within a sample, the quantification of known materials, the determination of the structure, and chemical properties of different molecules.

A mass spectrometer is composed of an ionization source, an analyzer, and a detector. The process involves the ionization of chemical compounds to generate ions. When using inductively coupled plasma (ICP), samples containing elements of interest are introduced into argon plasma as aerosol droplets. The plasma dries the aerosol, dissociates the molecules, and then removes an electron from the components to be detected by the mass spectrometer. Other ionization methods such as electrospray ionization (ESI) and matrix assisted laser desorption ionization (MALDI) are used to analyze biological samples. Following the ionization procedure, ions are separated in the mass spectrometer according to their mass-to-charge ratio (m/z), and the relative abundance of each ion type is measured. Finally, the detector commonly consists in an electron multiplier where the collision of ions with a charged anode leads to a cascade of increasing number of electrons, which can b

 Science Education: Essentials of Biochemistry

Tandem Mass Spectrometry

JoVE Science Education

In tandem mass spectrometry a biomolecule of interest is isolated from a biological sample, and then fragmented into multiple subunits in order to help elucidate its composition and sequence. This is accomplished by having mass spectrometers in series. The first spectrometer ionizes a sample and filter ions of a specific mass to charge ratio. Filtered ions are then fragmented and passed to a second mass spectrometer where the fragments are analyzed. This video introduces the principles of tandem mass spectrometry, including mass-to-ratio selection and dissociation methods. Also shown is a general procedure for analyzing a biochemical compound using tandem mass spectrometry with collision-induced dissociation. The applications section covers selection reaction monitoring, determination of protein post-translation modifications, and detection of tacrolimus levels in blood. Tandem mass spectrometry links together multiple stages of mass spectrometry to first isolate a biomolecule, and then determine aspects of its chemical makeup. Biomolecules have large, complex structures, making it difficult to determine their molecular composition. Tandem mass spectrometry selects a molecule of interest that is later fragmented into multiple subunits, which can help elucidate its identification and sequence. This video will show the

 Science Education: Essentials of Biochemistry

MALDI-TOF Mass Spectrometry

JoVE Science Education

Matrix-assisted laser desorption ionization (MALDI) is a mass spectrometry ion source ideal for the analysis of biomolecules. Instead of ionizing compounds in the gaseous state, samples are embedded in a matrix, which is struck by a laser. The matrix absorbs the majority of the energy; some of this energy is then transferred to the sample, which ionizes as a result. Sample ions can then be identified using a time-of-flight analyzer (TOF). This video covers principles of MALDI-TOF, including matrix selection and how TOF is used to elucidate mass-to-charge ratios. This procedure shows the preparation of a MALDI plate, the loading of samples onto the plate, and the operation of the TOF-mass spectrometer. In the final section, applications and variations are shown, including whole-cell analysis, characterization of complex biological samples, and electron spray ionization. Matrix-assisted laser desorption ionization, or MALDI, is a mass spectrometry ion source ideal for the analysis of biomolecules. Most ion sources remove structural information from large, fragile biomolecules. MALDI maintains structural integrity, and therefore information, while accelerating the molecules into the mass analyzer, which separates the compounds based on size and charge. The most commonly coupled with MALDI is the time of flight, or TOF,

 JoVE Medicine

Quantification of the Immunosuppressant Tacrolimus on Dried Blood Spots Using LC-MS/MS

1iC42 Clinical Research and Development, University of Colorado, Anschutz Medical Campus, 2Division of Clinical Pharmacology, Cincinnati Children's Hospital Medical Center, 3Food and Drug Administration (FDA), Center of Drug Evaluation Research - Office of Generic Drugs, 4Transplant Clinical Research, University of Cincinnati


JoVE 52424

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