Answer to Question #19997 in Inorganic Chemistry for Mary
What is the most widely used isotope in the world does not occur in nature? What are some of its application?.
In proteomics , the study of the full set of proteinsexpressed by a genome , identifying diseases biomarkers can involve the usageof 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. Themethod used to be about selectively enrich nuclei with 13 C or 15 N or deplete 1 H from them. The recombinant would beexpressed in E.coli with media containing 15 N- ammonium chloride as a source of nitrogen. [ 14 ] The resulting 15 N labeled proteins are then purified by immobilized metal affinity and their percentage estimated. In order to increase the yield of labeledproteins 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. [ 15 ] Another application of isotope labeling would be in measuring DNA synthesis,that is cell proliferation in vitro. uses H 3-thymidine labeling to compare pattern of synthesis (or sequence) in cells.