Hybridization between complementary DNA oligonucleotides was performed in the real time monitoring flow analysis system, BIAcore. Avidin was covalently immobilized to a dextran matrix and served as the reaction surface. Biotinylated oligonucleotides, introduced within a fluid stream, were captured by the immobilized avidin. Complementary DNA oligonucleotides successfully hybridized with the biotinylated base probes. The hybridization reaction was carried out at room temperature and positive signals were obtained within 7 min. In addition, biotinylated and complementary DNA oligonucleotides were prehybridized prior to injection. Hybrid pairs were captured by the avidin surface giving results commensurate with the concentrations injected. Control experiments showed that identically sized, but dissimilar DNA oligonucleotides did not hybridize with the biotinylated base probe. Nonspecific attachment of DNA directly to the reaction surface was not observed. This is the first account of specific hybridization occurring in real time within a fluid flow system detectable in less than 10 min at room temperature. © 1993 Academic Press. All rights reserved.
