Improvement of bacterial genomic DNA extraction in clinical specimens

Objective To optimize bacterial genomic DNA extraction methods of clinical specimens.Methods Different methods of bacterial genomic DNA extraction from pure cultures and clinical specimens were compared.Bacterial DNA Kit,pyrolysis,lysozyme,and the modified method(pyrolysis alkaline lysis combination method) were used.Results The genomic DNA extraction from pure cultures with Bacterial DNA Kit,lysozyme and combination method were be sufficient for PCR amplification(100%).However,the success rate of Gram positive bacteria was 0% with the pyrolysis method.Comparing the Bacterial DNA Kit and the pyrolysis alkaline lysis(NaOH over 20 mmol/L and 2% SDS) for clinical specimens,we found these two both methods were equal for PCR amplification,and concentrations of NaOH and SDS were key factors.Conclusion Pyrolysis alkaline lysis method was suitable for genomic DNA extraction in clinical specimens.