对虾免疫机能评估中样本容量的研究

Study on sample size in immunity assays of Fenneropenaeus chinensis

以中国明对虾(Fenneropenaeus chinensis)幼虾为试验材料,研究了样本容量对中国明对虾群体免疫水平评估准确性的影响。以黄嘌呤氧化法(试剂盒)测定对虾腹肌中的超氧化物歧化酶(SOD)活性,采用Hultmark等人的改进方法测定溶菌酶(LSZ)活性,以血球计数板法测定总血淋巴细胞密度(THCs)。结果表明,所采用的SOD、LSZ和THCs测定方法的测定平均变异系数分别为±2.34%、±4.67%和±4.58%。当样本的测定值的预设置信区间在试验误差允许范围之内,可以认为样本测定值能准确反映群体的水平。若以测定方法的平均变异系数为试验允许误差,当测定的置信水平取95%时,样本量分别为80、70、120时测得的结果能准确反映试验条件下中国明对虾群体的SOD、LSZ和THCs水平。当测定的置信水平取90%,样本量分别为50、50、80时测得的结果能准确反映试验条件下中国明对虾群体的SOD、LSZ和THCs水平。

The relationship between sample size and the accuracy in the assays on immune activity of population of Fenneropenaeus chinensis was studied. The superoxide dismutase （SOD） activity, lysozyme （LSZ） activity and the total haemocyte counts （THCs） of the juvenile shrimp were detected with xanthine-oxidation method, advanced Hultmark method, and haemocytometer method, respectively. The mean coefficient of variation of the three assays were ± 2.34%, ±4.67% and ± 4.58% respectively. When a predefined confidence zone of the sample＇s observation located in the range of acceptable error, the observation on samples reflected the real state of the population. When the mean coefficient of variation of the assays was regarded as the acceptable errors of the detections, and a 95% confidence level of the observation was adopted, the sample sizes of 80, 70 and 120 were needed for the accurate reflection of the real SOD, LSZ and THCs of the population respectively. If a 90% confidence level of the observation was adopted, the sample sizes for the reflection of real SOD, LSZ and THCs of the shrimp population were as large as 50, 50, 80 resoectively.