FLUORESCENCE DETECTION OF DNA USING A NOVEL PEROXIDASE SUBSTRATE, 4-(4-HYDROXYPHENYLCARBAMOYL)BUTANOIC ACID

lambda phage DNA on nitrocellulose filters was quantified by a fluorom etric assay using a biotin-labeled DNA probe and a p-acetamidophenol a nalog that yield a fluorescent product by enzymatic oxidation. Biotiny lated lambda,phage DNA (Hind III digested), used as a DNA probe, was p repared by diazobiotin, which reacts at the phosphate moiety of DNA. P eroxidase-labeled avidin was bound to biotin-labeled DNA, which was hy bridized with lambda DNA on a nitrocellulose filter. The DNA was detec ted using a fluorogenic substrate for peroxidase, 4-(4-hydroxyphenyl-c arbamoyl)butanoic acid (HPBA) in the presence of hydrogen peroxide. Th e assay permits the determination of lambda phage DNA as low as 0.1 pg by a flow-through system.