CruzQuench™ 3 phosphoramidite is designed to be a superior quencher to TAMRA, CFLsm3 and Cy3. CQ3 has (a). much stronger absorption; (b). much higher quenching efficiency; and (c). versatile reactive forms with desired solubility for labeling oligonucleotides and peptides. This CQ3 product is primarily used for the in-synthesis labeling of oligonucleotides.