Measuring Resistance to Virus Infection

Abstract

Dilution series of viruses often do not fit the exponential curve which they should fit if the usual assumptions of the theory of dilution series were true. Suppose the density of the virus suspension is λ, the average number of virus particles per unit volume of the inoculum (we suppose that unit volume is the amount actually used in inoculating the egg or other test material). Let C be the proportion of infective virus so that Cλ is the effective density of virus particles, and X is a factor depending on the dilution used such that CλX is the expected number of infective particles in the inoculum.