Topoisomerase I (E. coli) catalyzes the relaxation of negatively supercoiled DNA. Topoisomerase I is purified from a recombinant E.coli strain.

Concentration & Storage Condition
- 5 unit/㎕. Store at -20℃.

Storage Buffer
- 10 mM Tris-HCl, pH 7.5, 35 mM (NH₄)₂SO₄, 50 mM KCl, 1 mM DTT, 0.1 mM EDTA, 50% glycerol.

10x Reaction Buffer
- 20 mM Tris-acetate, pH 7.9, 50 mM potassium acetate, 10 mM magnesium acetate, 1 mM DTT.

Unit Definition
- One unit is defined as the amount of enzyme that catalyzes the relaxation of > 95% of 0.5 ㎍ of pUC19 (negatively supercoiled) DNA for 15 min at 37°C in a total reaction volume of 25 ㎕. DNA supercoiling is assessed by agarose gel electrophoresis.

QC Tests

- Activity, exo and endonuclease activity test, SDS-PAGE purity, performance tests.