Detection of DNA hybridization using the TISPR-1 surface plasmon resonancebiosensor

Biotinylated oligonucleotide probes were immobilized to the gold sensor sur face of the TISPR-1 miniature integrated surface plasmon resonance liquid s ensor system for the purpose of detecting specific DNA hybridization, The i mmobilization of the oligonucleotide capture probes was carried out through streptavidin-biotin binding technology. The sensor detected the immobiliza tion of unlabeled DNA through shifts in index of refraction as the molecule s entered and remained selectively bound to the surface in the vicinity of the exponentially decaying surface plasmon resonance wave. The surface immo bilization chemistry was proven to be stable for long periods of time, repr oducible, and practical for detecting DNA hybridization with the TISPR-1. D NA hybridization was detected as a slow, positive, and small (when compared to protein-protein or antibody-antigen binding experiments) increase in th e measured index of refraction under passive hybridization conditions by th e TISPR-1 sensor. The DNA hybridization signal was significant (index of re fraction change of 0.001) when large fragment PCR-amplified DNA products we re hybridized to the oligonucleotide probes (S/N = 6-10). The DNA hybridiza tion techniques were demonstrated using DNA sequences from the HIV genome w hich encode the Tat and Rev genes. (C) 1999 Academic Press.