There was a linear relationship between the logarithm concentration of actinomycin 23 21 ( c) and the diameter of inhibition zone ( mm), when the concentration of the antibiotic was in the range of 0.91 4.37 ug. 当放线菌素23-21的浓度为0.91~4.37μg/ml时,其抑菌圈直径与反应剂量有线性关系。经生物学统计分析,实验结果可靠。