Two Improved Extraction Methods of DNA in Unknown Bacteria

[Objective] The aim was to study the extraction method of DNA in bacteria so as to supply methodological support for studying unknown bacteria.[Method] The 2 extraction methods of DNA in bacteria were compared in aspects such as purity of DNA,enzyme digestion effect of genome DNA and gene amplification of 16S rRNA.[Result] The purity of DNA(OD260/OD280)extracted by method 1 was between 1.51 and 1.65 and the average purity of the 6 samples was 1.56.The purity of DNA extracted by method 2 was between 1.25 and 1.41 and the average purity of the 6 samples was 1.33.The purity of DNA extracted by method 1 was higher,but its expeirmental procedure was a little tedious.The expeirmental procedure of method 2 was a little simple,but its experimental duration was longer.The genome DNA longer than 21 kb in bateria was extracted by the 2 methods.The bands with length being about 600 bp were obtained from the PCR amplification of DNA extracted by the 2 methods and their amplification effects were better.[Conclusion] The quality of DNA extracted by the 2 methods was relatively high and both of them could be used in RFLP and PCR study directly.