Abstract
Inhibitory factor was induced by RTG-2 cell infected with IHN virus. This factor fulfilled the following biological and physicochemical properties.
1) thermostability to heating at 56°C for 30min. 2) acid stability to pH 2 at 4°C for 24hr. 3) nonsedimentation at 100, 000×g at 4°C for 2hr. 4) nondialysis. 5) inactivation by trypsin treatment. 6) cell specific specificity in antiviral effect. 7) wide antiviral spectrum. 8) indirect viral inactivation.
Three assays of interferon units were compared. The result indicated that dye uptake method was most sensitive assay, which was 2.1 times as sensitive as plaque reduction method and 2.6 times as sensitive as CPE method. Consequently, it was demonstrated that the factor was interferon.
