DMSO effect on assay performance and hRSV Long strain MOI titration. A) Serial 2-fold dilutions of DMSO in assay media, along with RSV Long strain [MOI = 0.2], were added to 2000 HEp-2 cells in 384 well plates. Six days post-infection, the cytopathic effect (CPE) of DMSO was assessed using Cell Titer Glo. B) Percent cell viability versus increasing MOIs on days 3 – 6 post-infection. CPE was assessed using Cell Titer Glo.