MB 633 NHS Ester is a fluroescent agent with a terminal NHS ester group. MB 633 NHS Ester very hydrophilic, water-soluble far-red fluorescent dye that has a maximal absorption of 630 nm and emission at 650 nm. The NHS ester can be applied to label the primary amines (-NH2) of proteins, amine-modified oligonucleotides, and other amine-containing molecules. Reagent grade, for research purpose. Please contact us for GMP-grade inquiries.