Detect non-specific endonucleases in type II restriction endonuclease EcoR I

The non-specific endonuclease is one of the important factors affecting the quality of type II restriction endonucleases.In this study,taking the EcoR I as an example,ΦX174 RF I DNA as substrate,the authors designed a testing method for detecting non-specific endonuclease in type II restriction endonucleases.The experimental results showed non-specific endonucleases were not detected in 90 U EcoR I,and the results of systematic methodology study indicated that the suggested method was stable,reproducible,and its detection limit could reach 0.1 U/90 U.