DETECTION OF NUCLEIC-ACIDS IN THE ATTOMOLE RANGE USING POLYBIOTINYLATED OLIGONUCLEOTIDE PROBES

This article describes the optimization of the hybridization signal ob tained with biotinylated oligonucleotides. Optimal number and position s of biotin moieties on a 33-base oligonucleotide probe were determine d. The quality of avidin-peroxidase conjugate and the choice of chromo genic substrate influenced detection sensitivity. A signal amplificati on method was also developed for avidin enzymatic conjugates. These im provements allowed the detection of less than 0.02 finol of target DNA .