A Comparative Study on Bacteria DNA Extraction Methods Used for PCR Amplification

The 16S rRNA genes amplification effects of the four simple total DNA extraction methods(freeze-thaw,boiling,alkaline lysis,and ROSE) were compared by extracting DNA from the Gram-negative and gram-positive bacterial strains of 14 genera.The results showed that the extraction effects of the methods from superior to inferior were in the following order: freeze-thaw,boiling,alkaline lysis and ROSE.The freeze-thaw method had advantages of cost-effective,time-and labor-saving and non-pollution.However,it was not always effective for minority gram-positive bacteria.When the DNA extraction of a large number of bacterial strains was required,the freeze-thaw method to extract total DNA of most bacteria may be first used.For the minority of DNA extraction samples which failed,it was advisable to discard the suspension from the freeze-thaw method,then use the chemical methods such as CTAB,SDS or DNA extraction kit for supplement.The freeze-thaw method to extract total DNA could not only save time and reduce cost,but also decrease the production of organic waste during DNA extrction.