Site-specific labeling technique refers to the covalent attachment of molecules like biotin, fluorophore, enzyme and radioactive isotopes to specific sites of the target protein. Protein labeling is extensively used to enable the detection and purification of the desired protein, and to facilitate the tracking of protein expression, localization, interaction, activity and conformational changes in complicated cellular signaling events.Profacgen has developed a series of protein labeling techniques and reagents to meet your research requirements. The most popular labels our customers choose include fluorescent probes (Phycoerythrin, allophycocyanin, fluorescein, tetramethylrhodamine, fluor dyes), enzyme conjugates (horseradish peroxidase and alkaline phosphatase) and biotin. We also provide N15 & C13 labeling for your NMR experiments. http://www.profacgen.com/protein-labeling.htm