基于标准物质评价平板计数琼脂培养基的生长率

目的：建立一种平板计数琼脂（plate count agar，PCA）培养基的生长率的评价方法。方法：使用待测PCA培养基对大肠杆菌标准物质进行测定，并根据公式计算大肠杆菌在待测PCA培养基上的生长率。对建立的评价方法的重复性和再现性进行验证。并使用建立的方法对9个品牌PCA培养基的生长率进行评价。结果：所建评价方法的重复性相对标准偏差为9.09%，再现性相对标准偏差为14.42%。不同品牌PCA培养基的生长率存在差异，但都满足0.83≤P_R≤1.17的要求。结论：本研究成功建立了一种基于标准物质的培养基质量评价方法，该方法具有重复性和再现性，可以快速高效评价PCA培养基的生长率。

Productivity Ratio Evaluation of Plate Count Agar Based on Reference Materials

Objective:To establish a method for evaluating the productivity ratio of plate count agar(PCA)based on reference materials.Methods:The reference material of Escherichia coli(E.coli)was tested using PCA,and then the productivity ratio of E.coli on the evaluated PCA was calculated according to the formula.The repeatability and reproducibility of the established method were verified in the study.In addition,the productivity ratio of 9 brands PCA was evaluated by the established method.Results:The RSD of repeatability of the established method was 9.09%,and the RSD of reproducibility was 14.42%.The productivity ratios of 9 brands PCA could face with the requirements of 0.83≤P R≤1.17,although there were differences between them.Conclusion:A method for quality control of the culture medium based on the reference material was successfully established,which showed a good repeatability and reproducibility,and could effectively evaluate the productivity ratio of PCA rapidly and efficiently.