Fig. 1.

Purification, effect of GRFT on cells viability and PDCoV infectivity. (A-B) SDS-PAGE and western blot analysis of purified GRFT. Lane M protein size markers, Lane 1 elution of GRFT, Lane 2 wash buffer through the resin, Lane 3 supernatant of lysed suspension. The molecular weight is about 15 kD. (C) ST and IPI-2I cell viability after 24 h incubation with different concentrations of GRFT by CCK-8 Kit. CC₅₀ (50 % cytotoxic dose) was figured by cell viability (%). (D) ST and IPI-2I cell viability after 24 h incubation with different concentrations of GRFT and PDCoV at MOI = 1. EC₅₀ (50 % effective dose) was figured by inhibition rate (%). (E) The therapeutic index (SI) was figured by CC₅₀/EC₅₀. The SI showed GRFT had good safety and anti-infection activity.