MB 680R NHS Ester is a fluroescent agent with a terminal TFP ester group. MB 680R NHS Ester very hydrophilic, water-soluble far-red fluorescent dye that has a maximal absorption of 685 nm and emission at 709 nm. The compound is pH-insensitive from pH 4 to pH 10. 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.