DNA topoisomerase IV (the parC-parE complex) converts the concatenated DNA into decatenated DNA. The DNA Topoisomerase IV Assay Kit is based the principle that the decatenated DNA is separated from the concatenated DNA by a quick and easy spin-column process.  The concatenated DNA stays on the column, while the decatenated DNA is eluted.  The eluted DNA is quantified by fluorescence.

DNA decatenation assays (96-well plate format): 

DNA decatenation assays for topoisomerases in 96-well plate assay format are available for high-throughput screen of topoisomerase inhibitors.