Quantitation of early, intermediate, and late mRNAs. BS-C-1 cells were infected in triplicate with 5 PFU/cell of vA8myx, vA8myxΔA26, vA8myxΔG6, vA8myxΔA26ΔG6 or WT virus. At 4 and 8 h postinfection (hpi), the cells were harvested and RNA extracted. Following reverse transcription, the cDNAs were quantitated by ddPCR using primers specific for I3, D13, and A3 mRNAs.