采用冷冻真空干燥法保存肝微粒体酶（S_9）的探讨

THE STUDY ON THE PRESERVATION OF MICROZOMAL ENZWE(S9)BY LYOPHILIZATION

本实验采用冷冻真空干燥法保存肝微粒体酶（Ｓ９），经过冻干前后，冻干后一年及冻干后二年零四个月各时间点测试，结果表明，冻干Ｓ９与新鲜制备的Ｓ９活性比较一致，冻干Ｓ９对间接诱变剂２ＡＦ具有活化作用。实验结果表明：采用冷冻真空干燥法保存肝微粒体酶Ｓ９是可取的。

Anes test has been used widely to examine the mutagenicity of environmentalchemicals and S9 metabolic activation system is essential to the test. Researchers have toprepare S9 from rat by pcb each time Because S9can only be stored for long time under-130℃, which is not provided in most laboratories in China. Each lot of S9 so preparedshowed differnce in activity and thus influences the experimental results. Thereforelyophilization procedure was adopted to prepare and store S9. The S9 so prepared werestored for 24hr, one year and 21/2years respectively. The number of revertants from allfour lots of S9 were recorded in Ames test in which TA98 and TA100 strains were used. Theresult showed that the activity of S9 after storage didn't change significantly. The benefitsfrom using lyophilized S9 are :(1) it can be produced in large scale and supplied as acommercial product;(2) the results of Anes test performed in different laboratories arecomparable;(3)the results between different experiments in the same laboratory arecomparable;in a word the quality of Ames test and/or other invitro tests using S9 would e improved.