Abstract: Fluorescence polarization methods for detection of nucleic acid amplification at thermophilic temperatures employ a fluorescently labeled oligonucleotide signal primer which is converted from single- to double-stranded form in a target amplification-dependent manner. This conformational change is accompanied by an increase in fluorescence polarization values. The decrease in FP typically observed for the duplex at elevated temperatures is overcome by double-stranded DNA binding proteins which are believed to stabilize the double-stranded structure by reducing the single-strandedness normally associated with higher temperatures. The inventive methods provide a closed, homogeneous system for amplification and detection of amplification in real-time or at an endpoint.

Abstract: The present invention provides methods for detecting amplified or unamplified nucleic acid target sequences at increased temperatures by changes in fluorescence polarization. The decrease in fluorescence polarization associated with hybridization of oligonucleotides at higher, more stringent, temperatures is overcome by including a double-stranded DNA binding protein in the assay. At elevated temperatures, the double-stranded DNA binding protein restores, and often enhances, the magnitude of the change in fluorescence polarization associated with single- to double-stranded conversion of an oligonucleotide probe or primer.