IMPROVED METHOD FOR STAINING CELL MONOLAYERS FOR VIRUS PLAQUE COUNTS

Abstract

A simple method for staining cell monolayers for virus plaques is described. A low agar concentration (0.6%) is employed in the overlay medium. When virus plaques have attained optimal size the agar overlay medium is removed and the firmly adherent non-cytopathically-affected cells of the monolayer are fixed and stained with crystal violet. This procedure gives sharply defined clear plaques with many enteroviruses and other mammalian viruses. Plaque bottles can be retained indefinitely as a record of plaque size, count, and morphology.