Patent ID: 7838230

Claim:
A method of assessing or measuring the ability of an enzyme to modify the supercoil topology of a target nucleic acid, the method comprising the steps of: (a) providing a solid support to which a capture nucleic acid is or can be immobilised, which capture nucleic acid is capable of binding the target nucleic acid in a manner that is proportional to the supercoil topology of said target nucleic acid; (b) incubating a test mixture comprising (i) the enzyme, (ii) the target nucleic acid, (iii) capture nucleic acid, in the presence of (iv) said solid support, such that supercoiled target nucleic acid bound by the capture nucleic acid is immobilised to the solid support, and (c) determining the amount of target nucleic acid bound by said capture nucleic acid in step (b), wherein the target nucleic acid comprises at least one region or insert capable of forming a triplex with the capture nucleic acid.