CruzQuench™ 7 maleimide is designed to be a superior quencher to Cy7, TF7 and Alexa Fluor 750. TQ7 has (a). much stronger absorption; (b). much higher quenching efficiency; and (c). versatile reactive forms with desired solubility for labeling oligonucleotides and peptides. This TQ2 product is used for post-labeling of thiol-modified oligonucleotides and cysteine-containing peptides.