Cell synchronization and monitor of their synchronous progression through the S-phase with and without DNA topoisomerase 2.

<p>top2-td cells transformed with the circular minichromosome pYAC_MEM were synchronized at the G1-S boundary and released synchronously into the S-phase at either permissive or restricted conditions. Samples were taken at regular intervals, the cells stained with SYTOXGreen and analyzed by flow cytometry. The data corresponding to fluorescence-activated cell sorting analysis of DNA content is shown. For comparison, top2-td curves from cells grown at the permissive temperature are indicated in pale gray for the diagrams of cells grown at the restrictive conditions.