SY-7 NHS ester

SY-7 NHS Ester (QSY®-7 succinimidyl ester equivalent) is a nonfluorescent acceptor dye for preparation of peptide and oligonucleotide FRET probes. A broad and intense quenching range from 500-600 nm makes it useful as an acceptor in fluorescence resonance energy transfer (FRET) applications in conjunction with fluorescent dyes at 520 nm to 600 nm, such as Fluorescein, Oregon Green, Carboxyrhodamine 110 (Rhodamine Green), Alexa Fluor® 488, 532, 546, 555, 568, Cy3, TAMRA and ROX dyes.

The NHS ester (or succinimidyl ester) is the most popular amine reactive group for labeling with the primary amines of proteins (Lys), amine-modified oligonucleotides, and other amine-containing molecules. The labeling occurs most efficiently at pH 7-9 and forms a stable, covalent amide bond.