One unit of topoisomerase II is defined as the amount of enzyme which can decatenate 0.2µg of KDNA in 30 min. at 37°C.
Technical Info / Product Notes
Two buffers that are used to prepare a final 10X working stock of assay buffer are provided: Note that the final 10X Complete Buffer contains both A and B and should be made fresh daily! 1. 10X Incomplete Buffer A contains the following: 0.5M TRIS-HCl (pH 8.0), 1.2M KCl, 0.1M MgCl2, 5mM dithiothreitol). [0.5mL provided] 2. 10X ATP Buffer B contains 50mM ATP in water [50µl provided]. These two buffers must be made fresh and mixed to make the final 10X Complete Topo II Assay Buffer (A+B) as follows. Simply add 0.1 volume of Buffer B to Buffer A. Prepare only as much of the Complete Topo II Assay Buffer (A+B) as needed for each day or set of experiments. For example: If you are performing 10 assays (20 µl/assay each) in a single day, you will need roughly 20 µl of the 10X Complete Buffer (20 µl/reaction x 10 reactions). You should prepare 25 µl of 10X Complete Buffer (A+B) by mixing 25 µl of Incomplete Buffer A (-ATP) and 2.5 µl of ATP Buffer B. Note that this buffer should be kept on ice and used the same day, then discarded.
Use/Stability
Stable for 1-2 days at +4°C. Buffers A and B should be kept at -20°C. The enzyme needs to be kept at -80°C.
Handling
After opening, prepare aliquots and store at -80°C. Avoid freeze/thaw cycles.
