Stable Isotope Labeling
Stable Isotope Labeling - Related Videos
11:53
Quantitative Proteomics Using Reductive Dimethylation for Stable Isotope Labeling
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Cited by 38 •
2014
Stable isotope labeling of peptides by reductive dimethylation (ReDi labeling) is a rapid, inexpensive strategy for accurate mass spectrometry-based quantitative proteomics. Here we demonstrate a robust method for preparation and analysis of protein mixtures using the ReDi approach that can be applied to nearly any sample type.
14:57
DNA Stable-Isotope Probing (DNA-SIP)
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Cited by 70 •
2010
DNA stable-isotope probing is a cultivation-independent method to identify and characterize active communities of microorganisms that are capable of utilizing specific substrates. Assimilation of substrate enriched in heavy isotope leads to incorporation of labelled atoms into microbial biomass. Density gradient ultracentrifugation retrieves labelled DNA for downstream molecular analyses.
07:12
Tracing de novo Lipids using Stable Isotope Labeling LC-TIMS-TOF MS/MS
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2024
Presented here is a method for screening lipid structures through stable isotope labeling by using their retention time, mobility, and fragmentation.
08:53
Quantitative and Qualitative Method for Sphingomyelin by LC-MS Using Two Stable Isotopically Labeled Sphingomyelin Species
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Cited by 2 •
2018
Here, we present a protocol to quantify and qualify each sphingomyelin species using multiple reaction monitoring and MS/MS/MS mode, respectively.
12:10
Stable Isotopic Profiling of Intermediary Metabolic Flux in Developing and Adult Stage Caenorhabditis elegans
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Cited by 12 •
2011
Stable isotopic profiling by gas chromatography mass spectrometric analysis of intermediary metabolic flux is described in the nematode, Caenorhabditis elegans. Methods are detailed for assessing isotopic enrichment in carbon dioxide, organic acids, and amino acids following isotope exposure either during development on agar plates or during adulthood in liquid culture.
FAQs
The method follows where labeled atoms appear after a nutrient or precursor enters a biological system. Their distribution and enrichment across metabolites can indicate how material moves through metabolic pathways, whereas abundance measurements alone show how much of a molecule is present. This distinction helps connect biochemical changes with pathway activity and cellular physiology.
The introduced compound determines which biological molecules can acquire the label and which biosynthetic origins can be examined. Carbon-13 and nitrogen-15 compounds, for example, can be incorporated into metabolites, proteins, lipids, or nucleic acids. Selecting a relevant precursor therefore focuses the analysis on particular pathways, products, or molecular transformations.
Mass spectrometry and nuclear magnetic resonance provide complementary ways to detect isotope distribution and enrichment. These measurements show whether labeled atoms entered particular molecular products and how strongly they are represented. The resulting patterns support analysis of metabolic pathways, biosynthetic origins, and changes in biological systems without relying on radioactive detection.
A typical workflow introduces a labeled nutrient or precursor to the biological system, allows cells to incorporate its atoms into relevant molecules, and then measures labeling patterns with mass spectrometry or nuclear magnetic resonance. Researchers interpret the observed distribution and enrichment across metabolites or other molecular classes to evaluate pathway behavior and molecular turnover.
The approach can reveal metabolic pathways, metabolic flux, biosynthetic origins, and protein turnover. It is useful when researchers need to determine how nutrients contribute to cellular products or how quickly molecular components are replaced. These measurements connect isotope incorporation with cell physiology and provide evidence about how biological systems respond to changing conditions.
Applications include studies of cell physiology, disease mechanisms, host-microbe interactions, and responses to treatment. In each setting, labeled atoms provide a way to examine molecular changes within the biological system under study. The resulting information can clarify altered metabolism, the origins of cellular molecules, or turnover patterns associated with disease or intervention.