实验室菌落计数精密度控制研究-Ⅱ方法研究

为使室间及室内检测数据的准确度及精密度控制控制在一定的范围,保证相关的卫生微生物实验室出具准确的检测数据,选用明胶菌片作为菌落计数室间及室内质控比对品。随机抽取明胶菌片和滤纸菌片各10片进行计数检测;取同一批号的明胶菌片发放给不同实验室进行室间比对;明胶菌片分别经1个月、3个月及6个月保存后进行稳定性计数测定。结果显示同一批次明胶菌片和滤纸菌片的相对标准偏差(RSD)分别为11%和223%,表明明胶菌片的精密度高于滤纸菌片;75个实验室室间明胶菌片计数结果95%的可信区间为551×107～803×107CFU片,有9683%的单位在此范围中;明胶菌片4℃冰箱保存1、3、6个月的检测结果的均数误差差异无显著性。采用明胶菌片作为菌落计数质控比对品,在精密度、准确度及可操作性方面都能达到相应的要求。

Study of accuracy of aerobic colony counting in laboratory-Ⅱ methodology

To control the accuracy of examination data in certain scope and ensure the related hygienic microbiological laboratory issues the accurate data, gelatin piece of bacteria was adopted as the contrast for quality control. The colony count of such gelatin pieces and filter paper pieces selected randomly were tested and their mean values of relative standard deviation ( RSD ) indicated that gelatin piece of bacteria provided more accurate result than the latter. Meanwhile, such wafers in one room and in different rooms and kept for different days were counted respectively, the results revealed that there were no remarkable difference among them. The results show that the gelatin piece of bacteria is appropriate for colony counting as contrast.