摘要
目的:研究鼠伤寒沙门氏菌回复突变试验(Ames试验)中菌液浓度和吸光度值[D(λ)值,λ为波长数值]的关系,开发通过吸光度值测定菌液浓度的方法。方法:选取Ames试验中常用的营养缺陷型鼠伤寒沙门氏菌TA102作为试验菌株,严格控制菌液扩增条件,对比分析540和600 nm波长下菌液的吸光度值的高低以确定最佳测定波长,对比分析菌株扩增0、2、4、6、8、10、12、14 h后的菌液浓度以确定最佳扩增时间。在最佳测定波长和最佳扩增时间下,测定菌液吸光度值,并通过平板菌落计数法测定菌液浓度,获得菌液浓度和吸光度值的回归方程。结果:菌株TA102的最佳测定波长为540 nm,最佳培养条件为37℃、100 r/min、10 h,菌液浓度和D(540)值的直线回归方程为y=4×10^9x[方程中x为D(540)值;y为菌液浓度,单位为个/mL]。结论:应用上述菌液浓度和D(540)值的直线回归方程,可通过测定D(540)值实时控制菌液达到要求浓度,从而确保试验菌液的质量。
OBJECTIVE:Relationships between bacterial concentrations and optical density[D(λ),λis the wavelength value]in the Salmonella typhimurium reverse mutation assay(Ames test)was investigated and a method for the determination of bacterial concentrations using optical density was developed.METHODS:TA102,a frequently-used auxotrophic Salmonella typhimurium in the Ames test,was selected as the test strain.The amplification conditions of the bacterial solution were strictly controlled.The wavelength of 540 and 600 nm were compared to choose the optimal wavelength for the determination of optical density,and the time of 0,2,4,6,8,10,12 and 14 hours were compared to choose the optimal times for amplification.Under the optimal wavelength and amplification time,the optical density of the bacterial solution was measured,and the bacterial concentration was obtained by plate colony-counting method.Then the regression equation between the bacterial concentration and the optical density was obtained.RESULTS:The optimal wavelength of strain TA102 was 540 nm,and the optimal culture condition was 100 r/min at 37℃for 10 hours.The linear regression equation between the bacterial concentration and D(540)value was y=4×10^9x(in the equation,x was D(540)value;y was bacterial concentration with the unit of/mL).CONCLUSION:Through the linear regression equation between the bacterial concentration and D(540)value,real-time control of the bacterial solution to reach the required concentration was achieved by measuring D(540)value,so as to ensure the quality of bacterial solution.
作者
周谡
李睿
朱鸿雁
张志超
方静
唐黎明
ZHOU Su;LI Rui;ZHU Hongyan;ZHANG Zhichao;FANG Jing;TANG Liming(Shanghai Institute for Food and Drug Control,Shanghai 201203;National Medical Products Administration Key Laboratory for Monitoring and Evaluation of Cosmetics,Shanghai 201203,China)
出处
《癌变．畸变．突变》
CAS
2020年第1期62-66,共5页
Carcinogenesis,Teratogenesis & Mutagenesis
基金
国家药典委员会课题(遗传毒性杂质风险评估关键技术研究)。
作者简介
周谡,E-mail:hello-world-zhou@163.com。通信作者:唐黎明,E-mail:tangliming@smda.sh.cn。
