QUANTITATIVE SEMIMICRO, SEMIAUTOMATED COLORIMETRIC ASSAY FOR INTERFERON

Abstract

The colorimetric assay for interferon, which utilizes a vital dye uptake for determination of cell viability, was adapted for semimicro quantities of cells and reagents and semiautomated techniques. Factors affecting interferon titer included the duration of interferon treatment of cells prior to [vesicular stomatitis virus] viral challenge, the multiplicity of viral challenge and the number of viral replicative cycles. Only the concentration, not the volume, of the interferon sample determined final titer, emphasizing that introduction of a volume term in a statement of interferon titer expresses interferon mass. The semimicroassay for interferon in both human [leukocyte and fibroblast] and mouse [fibroblast] cells proved precise, sensitive, convenient, reliable and relatively simple and rapid.