Abstract
λ phage DNA on nitrocellulose filters was quantified by a fluorometric assay using a biotin-labeled DNA probe and a p-acetamidophenol analog that yield a fluorescent product by enzymatic oxidation. Biotinylated λ phage DNA (Hind III digested), used as a DNA probe, was prepared by diazobiotin, which reacts at the phosphate moiety of DNA. Peroxidase-labeled avidin was bound to biotin-labeled DNA, which was hybridized with λ DNA on a nitrocellulose filter. The DNA was detected using a fluorogenic substrate for peroxidase, 4-(4-hydroxyphenylcarbamoyl)butanoic acid (HPBA) in the presence of hydrogen peroxide. The assay permits the determination of λ phage DNA as low as 0.1pg by a flow-through system.
