Tissue Cultures as a More Sensitive Method Than Animal Inoculation for Detecting Equine Encephalomyelitis Virus

Abstract

Cultures consisting of minced chick embryo tissue suspended in Tyrode's solution1 have been found favorable for the growth of equine encephalomyelitis virus. If it can be shown that cultures are equally or even more effective for revealing minimal quantities of virus in a material, or that cultures can bring to light the presence of virus when animal inoculation fails, a useful method will be available. Equally important is the fact that in a single test inoculum, a larger amount can be introduced into a culture than in an animal, since by intracerebral inoculation∗ a guinea pig can receive with safety a limiting quantity of only 0.2 cc., and a mouse 0.05 cc.A comparison was therefore made of the relative sensitivity of cultures and of intracerebral inoculation of mice and guinea pigs for detection of the virus.In Experiment 1, shown in Table I, a single disc Seitz filtrate of a 10% broth suspension of infected mouse brain tissue was diluted decimally to 10-8 dilution. Each of 4 mice received an intracere...