AMCA NHS Ester (succinimydyl-7-amino-4-methylcoumarin-3-acetic acid) is one of the most popular blue fluorescent tagging molecules. It is widely used to label antibodies, proteins and small drug molecules. Often used as contrasting probes for double- and triple-labeling in immunofluorescence microscopy, arrays and in situ hybridization. The desirable properties of AMCA dyes include a relatively large Stoke’s shift and resistance to photobleaching.
AMCA NHS Ester reacts specifically and efficiently with a primary amine (e.g., side chain of lysine residues or aminosilane-coated surfaces) at pH 7-9 to form a stable, covalent amide bond. The NHS ester (or succinimidyl ester) is the most popular tool for conjugating dyes to the primary amines of protein or antibody (Lys), amine-modified oligonucleotides, and other amine-containing molecules.