Establishing an efficient and safe method of plasmid dna extraction

A new,safe and efficient plasmid extraction method modified on the basis of alkaline lysis method was established,which changed alkaline lysis solutionⅡformula with the reduction of NaOH concentration from 0.20 mol/L to 0.1 mol/L to increase the quantity of extracted superhelical DNA.In order to prevent the high toxicity and volatile smell produced by phenol and chloroform in alkaline lysis method,the silica was used in this method to purify plasmid DNA.The results showed that the quality of extracted plasmid DNA isolated by the established method was better than that of classical alkaline lysis method evaluated by the electrophoresis and spectrophotometer quantitative analytical methods.The restriction enzyme digestion experiment also proved that the plasmid produced by new method can be used effectively for further recombination manipulation such as ligation and transformation.Furthermore, silica used in this method can be recycled to,which reduces experimental expenses to a large extent.