In vitro repair of oxidative and ultraviolet-induced DNA damage in supercoiled nucleoid DNA by human cell extract

A human cell extract is capable of carrying out damage-specific incision on supercoiled nucleoid DNA. The DNA breaks are detected by single cell gel electrophoresis. Incubation of the incised DNA with extract and DNA precursors results in resealing of the breaks, with retention of the supercoiled state of the DNA.