FAM Sulfo-NHS ester, Cat. No.: CWSN1025_1 mg, Excitation/Emission Max.(nm): 494/518, Storage conditions: -20 ℃, protect from light. FAM Sulfo-NHS ester is a reactive form of bright green dye used to generate a stable fluorescence signal in bioimaging. The maxima of Ex/Em values are at 494/518 nm, similar to that of Alexa 488 and Cy2. FAM might be excited using 488 nm laser line and displays good optical property. Sulfo-NHS esters have higher water solubility than NHS esters, thus they do not need organic co-solvent and readily react with amine-modified oligonucleotides or amino groups of proteins, i.e. the ε-amino groups of lysine or the amine terminus of nucleotides to form a stable amide bond between dye and the biomolecule. We offer FAM Sulfo-NHS ester for labeling of antibodies, peptides, proteins and nucleotide.