Application of Radioisotopes in Biochemical Analyses: Metal Binding Proteins and Metal Transporters

Radioisotopes (RI) such as 3H, 14C, 32P, and 45Ca are excellent tools in biological research. Most RI are used as tracers in studies of primary and secondary metabolism, drug metabolism, transcription, translation, post-translational modifications such as protein phosphorylation, association of proteins with metals, and transport of metals across biomembranes. Furthermore, some experiments have used neutrons for mutagenesis of microorganisms, animals, and plants. Recent progress in the biological sciences has resulted in novel probes and labeling reagents, which has decreased the need for RI. Experiments with RI require experimental space specialized for RI, careful experimental procedures, and training. Although these are disadvantages, RI are still useful and powerful tools with high resolution compared with non-RI methods. Here, we describe the advantages of RI in biochemical assays, and detailed experimental procedures of metal-binding assays and membrane transport measurements of metal cations, especially calcium and zinc.