Isotopic Labeling - Applications in Genetics

Applications in Genetics

In proteomics, the study of the full set of proteins expressed by a genome, identifying diseases biomarkers can involve the usage of stable isotope labeling by amino acids in cell culture (SILAC), that provides isotopic labeled forms of amino acid used to estimate protein levels. In protein recombinant, manipulated proteins are produced in large quantities and isotope labeling is a tool to test for relevant proteins. The method used to be about selectively enrich nuclei with 13C or 15N or deplete 1H from them. The recombinant would be expressed in E.coli with media containing 15N-ammonium chloride as a source of nitrogen. The resulting 15N labeled proteins are then purified by immobilized metal affinity and their percentage estimated. In order to increase the yield of labeled proteins and cut down the cost of isotope labeled media, an alternative procedure primarily increases the cell mass using unlabeled media before introducing it in a minimal amount of labeled media. Another application of isotope labeling would be in measuring DNA synthesis,that is cell proliferation in vitro. uses H₃-thymidine labeling to compare pattern of synthesis (or sequence) in cells.