Immunoelectron microscopy of mature extracellular PrV virions. Rabbit kidney cells were infected with PrV-Ka and analyzed 14 h after infection by either conventional (A) or immunoelectron microscopy using antisera against the UL31 (B), UL34 (C), UL36 (D), UL37 (E), UL46 (F), UL47 (G), UL48 (H), UL49 (I), or US3 (J) proteins. Bar, 200 nm.