Abstract
Strain Dairen I (DI) and strain IHD-T of neurovaccinia virus were readily inactivatedin HCl-citrate buffer solution, pH 2.2 or 2.6, at room temperature, 23 C, reaching about10-3 or less survival in 2 min and 10-4 or less in 5 min. Treatment of L cells with thebuffer solution, pH 2 to 2.5, at room temperature for 5 min after virus adsorption at37 C effectively reduced the titer of residual active virus, and provided a simple, effectivemethod to unmask the low-grade replication of strain DI with little deleteriouseffect on the cells. The method seems useful for the analytical study on the viralreplication, particularly the early virus-cell interactions. The clonal analysis, preliminaryin nature, of the viral yield of DI infected L cells provided data suggestive ofselection for viruses better adapted to L cells
