荧光标记法测定菌落总数

采用一种新型破膜剂麝香草酚将微生物细胞壁完全破裂，再用碘化丙啶荧光标记微生物核酸或DNA，测定荧光值。建立工作曲线，根据荧光值在工作曲线上查出菌落总数。结果表明，破膜剂麝香草酚的最适浓度为4 mmol/L，本方法测定枯草芽孢杆菌菌落数对应荧光值的相对标准偏差为1.29%，回收率为98.4%。方法准确可
靠，而且不需要大量铺平板，简便快速。

Determination of Total Number of Colonies by Fluorescence Labeling Method

After complete disruption of the microbial cell wall with thymol, the nucleic acids or DNAs were labeled with
propidium iodide for the detection of fluorescence values. A standard curve was established for extrapolating total number
of colonies based on the fluorescence values. The results showed that the optimal thymol concentration for breaking the
microbial cell wall was 4 mmol/L. The relative standard deviation of this method for the determination of the fluorescence of
B. subtilis colonies was 1.29%, and the recovery rate was 98.4%. This method is accurate, reliable, simple and rapid without
the use of a large amount of plates.