RESUMO
Objective To establish a simple , fast and economic total DNA extraction method to serve the rapid identification of model mouse genotype in large number of mice .Methods Three methods, i.e.phenol extraction, isopropyl alcohol precipitation and mouse ear boiling methods were used to extract the total DNA from ten C 57-rasmodel mice.The purity and yield of DNA obtained by the three methods were compared , and polymerase chain reaction ( PCR) assay was used to compare the efficacy of the three extraction methods .Results Among the three methods , phenol extraction was the best and isopropyl alcohol precipitation was the poorest in DNA yield .In terms of DNA purity , the phenol extraction was the best and the mouse ear boiling method was the poorest .All the three methods could be used to extract the total DNA from mice serving as template of PCR reaction for the mouse genotype identification .The time consumption of three methods are 12.5 hr ,13 hr and 0.18 hr.Mouse ear boiling method was significantly lower than that of the other two methods ( P <0.01 ) ,.The obtained total DNA can be stored at conventional -20℃for 7 days and 30 days later still can be used as a template for PCR reaction .Conclusions Among the three methods studied , the mouse ear boiling method is simple and with the lowest cost , so it is feasible for total DNA extraction in scaled genotyping experiments .
RESUMO
According to the characteristics of sludge samples from full-scale wastewater treatment bioreac-tors, the essential total DNA extraction method for most environmental samples, lysozyme-SDS-phenol/ chloroform method, was modified to improve sample pretreatment, intensify cell lysis and enhance the effi-ciency of impurity removal. Obtain a general total DNA extraction method for industrial sludge samples. Such a method was applied for total DNA extraction of sludge samples from several running full-scale an- aerobic or aerobic bioreactors in Shijiazhuang, China. The results indicated that the modified method was suitable for all the sludge samples in this study, showing the satisfying generality. The extracted total DNA of all sludge samples were pure, with about 1.8 of A260/ A280 ratio. The method was also efficient; with average total DNA yield of over 0.7 mg/g and maximum yield of 0.85 mg/g. Moreover, all the extracted to- tal DNA samples could serve as templates directly to amplify 16S rDNA by PCR. The PCR products could be separated well by denaturing gradient gel electrophoresis (DGGE) and the DGGE band patterns were clear enough to be used for further analysis. All these facts indicated that the total DNA extraction method provided in this study could meet the requirements of sludge samples research, from full-scale wastewater treatment bioreactors, using molecular biology technologies.
