Automated, quantitative cytopathic effect reduction assay for interferon.

A rapid, cytopathic effect reduction assay for human interferon (IFN) is described. Dilutions of IFN were made with an automated diluter in 96-well microtiter plates. Total incubation time was 26 h. IFN titers were calculated from optical density readings of crystal violet-stained monolayers in an automated spectrophotometer, which required less than 1 min to read each plate.