A Medium Free of Agar, Serum and Peptone for Plaque Assay of Herpes Simplex Virus.

Abstract

Summary Methods have been described for quantitative plaque assay of herpes simplex virus either in bottle culture or in Leighton tubes. The overlay employed was devoid of agar, peptones and serum, which are viewed as undesirable constituents. Use of agar overlay results in production of plaques from only a small fraction of the potential plaque-forming population. The inhibition of plaque formation by agar can be reversed by addition of protamine sulfate at a level of approximately 800 μg/ml. Possible uncertainties associated with the use of mixtures of agar and protamine can be avoided by substitution of methyl cellulose with which a further 10-fold increase in sensitivity of the assay was obtained.