A Simplified Colorimetric Test for Poliomyelitis Virus and Antibody

Abstract
The test is based on the metabolic activity of viable HeLa cells which produce acid from glucose when cultured in a medium consisting of Mixture no. 199, 5% heated monkey serum and added glucose. Phenol red indicator is changed from red to yellow. The cells are suspended in medium, counted and distributed in suspension to either virus dilutions or mixtures of dilutions of unknown viruses and sera. In the presence of unneutralized poliomyelitis virus the HeLa cells are destroyed; the medium''s color (red) remains unchanged. There was agreement between virus infectivity endpoints and antibody endpoints as determined by concomitant readings of color changes and cytopathogenicity.