Sensitivity of the erythrocyte micronucleus assay: Dependence on number of cells scored and inter-animal variability
Sensitivity of the erythrocyte micronucleus assay: Dependence on number of cells scored and inter-animal variability
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DOI：
10.1016/j.mrgentox.2007.07.010
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发表时间：
2007-12-01
影响因子：
1.9
通讯作者：
MacGregord, James T.
中科院分区：
文献类型：
--
作者：
Kissling, Grace E.;Dertinger, Stephen D.;MacGregord, James T.
直到最近，体内红细胞微核试验一直使用显微镜进行评分。由于微核细胞的频率通常较低，因此细胞计数存在显著的二项式计数误差。计数误差，沿着动物间变异性，限制了该测定的灵敏度。最近，已经开发了用于对微核红细胞进行评分的流式细胞术方法，这些方法能够评价比显微镜评分更多的细胞。使用小鼠、大鼠和犬中报告的典型自发微核频率，我们计算了与微核网织红细胞频率相关的计数误差，作为评分网织红细胞数量的函数。我们将该计数误差与通过对足够数量的细胞进行流式细胞术评分确定的动物间变异性进行比较，以确保计数误差小于动物间变异性，并计算可检测到的微核频率的最小增加作为评分细胞数量的函数。数据显示，当前的监管指南允许在自发频率低时测试的低功率（例如，
Until recently, the in vivo erythrocyte micronucleus assay has been scored using microscopy. Because the frequency of micronucleated cells is typically low, cell counts are subject to substantial binomial counting error. Counting error, along with inter-animal variability, limit the sensitivity of this assay. Recently, flow cytometric methods have been developed for scoring micronucleated erythrocytes and these methods enable many more cells to be evaluated than is possible with microscopic scoring. Using typical spontaneous micronucleus frequencies reported in mice, rats, and dogs we calculate the counting error associated with the frequency of micronucleated reticulocytes as a function of the number of reticulocytes scored. We compare this counting error with the interanimal variability determined by flow cytometric scoring of sufficient numbers of cells to assure that the counting error is less than the inter-animal variability, and calculate the minimum increases in micronucleus frequency that can be detected as a function of the number of cells scored. The data show that current regulatory guidelines allow low power of the test when spontaneous frequencies are low (e.g.,