Abstract
A simple chemical method for introducing biotin into nucleic acids has been developed for the synthesis of non-isotopic hybridization probes. The method is based on the reaction of biotin hydrazide with amino residues of nucleic acids by using glutaraldehyde as a bifunctional coupling reagent.Biotin-labelled deoxyribonucleic acid (DNA) was detected by the use of alkaline phosphatase-labelled avidin, and alkaline phosphatase activity was measured by colorimetric and chemiluminescence methods. The chemiluminescence method using the nicotinamide adenine dinucleotide phosphate (NADP)/alcohol/alcohol dehydrogenase/microperoxidase/isoluminol system gave the highest sensitivity. A few picograms of λ-phage DNA coated on a microtiter plate well could be detected by this method.
