includes 480 ul of 10 x Buffer HT1, 405 ul of 10 x supercoiled plasmid DNA, 10 ul of 1000 x human topoisomerase I enzyme (500U/ul), 20 ul of 1500 x Dye H19 and 3000 ul of 10 x H19 dilution buffer. includes all the reagents for 100 DNA relaxation assays in a 96-well plate format or 200 assays in a 384-well assay format.