Lc-ms/ms Profiling
Lc-ms/ms Profiling - Related Videos
08:29
Expression Profiling with Microarrays
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2023
Microarrays are important tools for profiling gene expression, and are based on complementary binding between probes that are attached to glass chips and nucleic acids derived from samples. Using these arrays, scientists can simultaneously evaluate the expression of thousands of genes. In addition, the expression profiles of different cells or tissue types can be compared, allowing researchers to deduce how the expression of different genes change during biological processes, and thus gain...
09:08
Sample Preparation for Metabolic Profiling using MALDI Mass Spectrometry Imaging
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Cited by 9 •
2020
The goal of this protocol is to provide detailed guidance on the sample preparation when planning for experiments using MALDI MSI to maximize metabolic and molecular detection in biological samples.
07:13
Using Topographic Maps to Generate Topographic Profiles
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2023
Source: Laboratory of Alan Lester - University of Colorado Boulder Topographic maps are "plan-view" representations of Earth's three-dimensional surface. They are a standard type of map-view that provides an overhead, or aerial, perspective. Among the defining features of a topographic map are the contour lines that indicate locations of constant elevation. The elevation interval between the contour lines is dependent on the level of detail provided by the map and the kind of topography present.
09:16
Eukaryotic Polyribosome Profile Analysis
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Cited by 51 •
2010
This article describes a protocol for the extraction of translating ribosomes from eukaryotic cells. Once extracted, ribosomes are separated into monosomes and polyribosomes by sucrose gradient fractionation to allow different ribosomal populations to be analyzed. As such, this method is the gold standard for examining the regulation of translation.
11:09
An Easy Method for Plant Polysome Profiling
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Cited by 20 •
2016
This protocol describes an easy method to extract and fractionate transcripts from plant tissues on the basis of the number of bound ribosomes. It allows a global estimate of translation activity and the determination of the translational status of specific mRNAs.
FAQs
Chromatography reduces the complexity presented to the mass spectrometer by resolving compounds before ion measurement. Each compound’s retention depends on its interactions with the stationary and mobile phases, so compounds reach the ionization and mass-analysis stages at different times. This separation helps organize measurements from biological mixtures and supports more interpretable metabolite, lipid, peptide, and protein profiles.
Fragmentation adds structural evidence beyond the mass-to-charge ratio of an intact ion. In the second mass-analysis stage, a selected ion is broken into product ions, and the resulting pattern acts as a structural fingerprint. This helps distinguish and characterize compounds within biochemical samples, rather than relying only on when they elute or on the parent ion measurement.
Qualitative profiling asks which chemical signals or compounds are present and examines their structural fingerprints, whereas quantitative profiling measures their levels. Using both perspectives allows a study to detect biochemical features and then assess how abundances differ among samples. That combination is especially useful when investigating changes associated with disease, treatment, or cellular processes.
Mass-to-charge measurements and chromatographic retention provide complementary dimensions of identification. Retention reflects how a compound interacts with the liquid-chromatography system, while the ion signal is characterized by its mass-to-charge ratio and fragmentation pattern. Considering these measurements together gives a richer chemical profile than any one measurement alone, supporting more confident biochemical interpretation.
A typical analysis proceeds by introducing a complex biological sample into liquid chromatography, allowing compounds to resolve, ionizing the separated compounds, and measuring their ions by mass-to-charge ratio. Selected ions then undergo a second mass-analysis step for fragmentation. The resulting retention, ion, and fragment information can be interpreted as qualitative or quantitative biochemical profiles.
The approach can profile metabolites, lipids, peptides, and proteins in complex biological samples. Its value comes from applying separation and tandem mass-analysis to chemically diverse components, allowing investigators to examine composition and abundance across biochemical systems. The resulting profiles support broad biochemical characterization rather than focusing on only one molecular class.
In biochemistry, LC-MS/MS profiling supports metabolomics, biomarker discovery, pathway investigation, and drug research. Researchers can compare qualitative and quantitative profiles to identify biochemical differences linked with disease, treatment, or cellular processes. These comparisons help connect measured chemical changes with broader questions about biological state, pathway behavior, and responses to an intervention.