Isotopes refer to elements of the same atomic number (number of protons) but different mass numbers (number of neutrons). According to different physical properties, isotopes can be divided into radioisotopes and stable isotopes. According to the different quality, isotopes can be divided into light isotopes and heavy isotopes.
Over the years, the absolute quantification (AQUA), based on isotope-labeled peptides has become a resultful means of quantifying proteins. AQUA can quantitatively study various complicated biological samples and provide valuable new tools for proteomics.
Isotope-coded derivatization (ICD) is a promising alternative to intraisotopic technology, that can be used to overcome matrix effects caused by coexisting substances that are common in liquid chromatography-mass spectrometry/mass spectrometry analysis of generations.
ICAT uses a new chemical reagent called isotope affinity labeling reagent to pre-selectively label a certain class of proteins. Then the labeled protein was separated and purified, and then identified by mass spectrometry (MS), and the relative abundance of its parent protein in the original cell was quantitatively analyzed according to the ratio of ionic strength of different peptide segments on the mass spectrometry.
DNA-stable isotope probing technology (DNA-SIP) is a molecular ecology technology that uses stable isotopes to trace the genomic DNA of microorganisms in complex environments. DNA-SIP technology mainly targets microbial communities and reveals microbial actors involved in the metabolic process of labeled substrates in complex environments.
Isotope ratio mass spectrometers (IRMS) are precision instruments used to determine isotope ratios. In addition to the well-known application of stable isotope geochemistry, currently, IRMS technology is also applicable to agriculture, medicine and environmental science and other research fields.
Stable isotope tracer technology uses stable isotopic tracer atoms or compounds to study the movement and transformation principles of the substances being traced. This method measures the content of the same non-labeled compound by detecting the change of the isotope ratio.
Isotope dilution mass spectrometry is a method in which stable isotope-labeled compounds of known mass and abundance are added to a sample as a diluent, mixed homogeneously, and then the change in isotope abundance before and after mixing is determined by mass spectrometry, and finally the elemental content of the sample can be calculated.