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当前,国际范围内所采用的Ames测试系统包括TA_(97)、TA_(98),TA_(100)、TA_(102)四种菌株.但是,TA_(97)菌株在应用上存在以下缺点;过夜培养的菌液活性较低、背景菌苔不明显,平皿上回复突变产生的菌落较细小.其原因与该菌株的uvrB基因缺失有关。因此,Ames实验室最近已对TA_(97)菌株进行了改进,改进后的重组菌株命名TA97a以代替原来的TA_(97)。TA97a的生长特性较TA_(97)为好,它对敌克松、二氨基芴、ICR-191等诱变剂的反应则与TA_(97)相同。但它在含葡萄糖的基础培养基(Minimal Medium)上则生长缓慢,这是由于
At present, the Ames test system adopted in the world includes TA_ (97), TA_ (98), TA_ (100) and TA_ (102) strains.However, the TA_ (97) strain has the following shortcomings in application; The activity of the cultured bacteria was low, the background of the lawn was not obvious, and the colonies produced by the repeated mutation on the plate were smaller, the reason was related to the deletion of uvrB gene of the strain. Therefore, the Ames laboratory has recently been TA_ (97) strains improved, the improved recombinant strain named TA97a to replace the original TA_ (97). The growth characteristics of TA97a was better than that of TA97 (97), and the reaction of TA97a with the mutagens such as EDX, diaminofluorene and ICR-191 was the same as TA_ (97). But it grows slowly on minimal medium with glucose, due to