A New in Vitro Method (END) for Detection and Measurement of Hog Cholera Virus and Its Antibody by Means of Effect of Hc Virus on Newcastle Disease Virus in Swine Tissue Culture

Abstract

A new in vitro method (END method) was developed for detecting and measuring hog cholera virus. This method is based on the following findings: a) that, under certain experimental conditions, Newcastle disease virus exerts no cytopathic effect when inoculated into swine testicular cell monolayer cultures within 4 or 5 days of cultivation, whereas Newcastle disease virus produces cytopathic changes when inoculated into the same culture after 6 to 8 days of cultivation; b) that in cell cultures infected in the initial stage of cultivation with hog cholera virus, which produces no cytopathogenesis, Newcastle disease virus readily produces marked cytopathic effects even if it is inoculated as early as the second, third, or fourth day of cell cultivation. Various factors involved in the phenomenon were investigated and a standard method of procedure was established.