Helicases convert double-strand DNA into single-strand DNA, a DNA unwinding process energized by ATP hydrolysis. DNA helicases are essential during DNA replication, repair, recombination and transcription. The Helicase DNA Unwinding Assay is based on measurement of the DNA unwinding activity using a fluorescence-labelled duplex DNA substrate. The fluorescence group Quazar 570 is linked to one strand of DNA and its fluorescence is quenched by the dye BHQ-2 that is linked to the other strand of DNA. Once the duplex DNA is separated by the helicase coupled with ATP hydrolysis, the single-strand DNA product is trapped by a trapping DNA and the fluorescence is regenerated.  It is a continuous assay. The DNA helicase assays can be performed in a 96-well plate or 384-well plate format for high throughput screening of DNA helicase inhibitors. 

The Helicase DNA Unwinding Assay Kit (Catalog No.  DU050K) includes 300 µl of 10 x assay buffer, 25 µl of 100 x  DNA duplex, 125 µl of 100 x trapping DNA and 25 µl  of 100 x ATP.   The kit is for 50 assays of DNA helicase assays in a 384-well assay format or 25 assay in a 96-well plate format.  The kit does not include the helicase.   

The Human DNA Polymerase Theta Helicase Assay Kit Plus (Catalog No. DU050PQ) includes includes 300 µl of 10 x assay buffer, 25 µl of 100 x  DNA duplex, 125 µl of 100 x trapping DNA, 25 ul of 100 x human DNA polymerase theta N-terminal domain and 25 µl  of 100 x ATP.   The kit is for 50 assays of DNA helicase assays in a 384-well assay format or 25 assay in a 96-well plate format.