中文摘要：

从处理某制药废水的MBR反应器中采集活性污泥,评价不同DNA提取方法对其总DNA提取效率的影响。DNA提取分细胞裂解和DNA纯化2步,对细胞裂解比较了珠磨匀浆法、反复冻融法、十二烷基磺酸钠（sodium dodecyl sul-fate,SDS）裂解法等7种方法;对DNA纯化比较了酚/氯仿纯化法和胶回收纯化法。结果表明,SDS裂解法、酚-氯仿纯化法最优。通过条件优化实验,确定SDS裂解-酚/氯仿纯化法在污泥量1.1 g,10 000 r/min离心5 min的操作条件下,获得的DNA产量（10 774μg/g泥重）和纯度（OD260∶OD280=1.84）等综合指标最好。

英文摘要：

Using activated sludge sample, which was collected from an experimental MBR treating pharmacy wastewater, several DNA extraction methods were evaluated. DNA extraction includes two steps of cell lysis and DNA purification. Firstly, seven cell lysis methods, including bead mill homogenization, freeze-thawing, SDS-based method, etc. Sencondly, two purifircation methods, phenol/chloroform purification and agarose gel purification were compared. The results showed that SDS-based method and phenol/chloroform purification were the best for each step. Furthermore, conditions of the SDS-based lysis-phenol/chloroform purification were optimized. The most DNA yield （ 10774μg/g sludge） and the best purity （ 09260： OD280 = 1.84.） were achieved under the conditions of using 1.1 g sludge sample and eentrifugating at 10 000 r/min for 5 min.