Detection of DNA hybridization with immobilized fluorescently labeled oligonucleotide probes using fluorescence polarization technique

摘要

A novel detection scheme in which DNA hybridization can be detected without target-labeling and washing steps was proposed. In this scheme, the free end of oligonucleotide probes immobilized on a streptavidin-coated cover glass was fluorescently labeled. Changes in the fluorescence anisotropy of the probes upon target hybridization were easily monitored. This scheme could easily be incorporated into a DNA chip or a high-density array. The fluorescence anisotropy was measured by using a fluorescence microscope equipped with polarizing devices and an image intensified CCD camera. The region where probes were hybridized with targets showed an increase in fluorescence anisotropy, which indicates that the interaction between the probe and target resulted in a concomitant change in the rotational relaxation time of fluorescent molecules and the measured fluorescence anisotropy.