【摘 要】
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Dear EditorrnThe most important property of a virus is its infectivity.To measure infectivity,one can assay viral replication in cells to obtain a titer for a given virus stock.A titer is defined as a given number of infectious viral units per unit volume
【机 构】
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Wuhan Institute of Virology,Center for Biosafety Mega-Science,Chinese Academy of Sciences,Wuhan 4300
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Dear EditorrnThe most important property of a virus is its infectivity.To measure infectivity,one can assay viral replication in cells to obtain a titer for a given virus stock.A titer is defined as a given number of infectious viral units per unit volume,and an infectious unit is the smallest amount of virus that produces recognizable effects[e.g.,cytopathic effect(CPE),dot blot immunoreactivity].The median tissue culture infectious dose(TCID50)is defined as the dilution of a virus required to infect 50％ of a given cell culture.Several methods have been developed to calculate the TCID50 including the Spearman-K?rber method(Spear-man 1908;K?rber 1931),the Reed-Muench method(Reed and Muench 1938),the improved K?rber method(Sun 1963),the Weil method(Meynell GG and Meynell E 1970),and probit/logit regression models(Finney 1971).In this letter,we analyze datasets using three popular methods for calculating the TCID50 in Excel based calculator(Supplementary file 1).We also compared these results with those of probit/logit regression models and discuss the differences among these methods.
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