CYTOCHEMISTRY OF CYTOPLASMIC AND INTRANUCLEAR INCLUSIONS INDUCED BY BOVINE PARAINFLUENZA 3 VIRUS (SF-4) IN HUMAN CELL CULTURES

Infection of human IIEp-2 cells with myxovirus bovine parainfluenza 3 (SF-4) induces the formation of cytoplasmic and intranuclear inclusions. Both types of inclusions were shown to contain some RNA in late stages (gallocyanin chromalum, azure B bromide, pyronin, RNase), abundant protein at all stages (acidic fast green, mercuric bromphenol blue) primarily with lysine-rich residues (naphthol yellow S, lysine blockage) and lesser amounts of arginine (Sakaguchi) and tyrosine (diazotization coupling). Inclusions failed to stain for histones (alkaline fast green, ammoniacal silver), basic proteins (alkaline Biebrich scarlet, picric acid-eosin). DNA (Feulgen, fluorescent-Feulgen, methyl green, gallocyanin chromalum, azure B bromide) and polysaccharides (fluorescent-PAS, Hale). There was a slight staining for histones with metaphosphoric acid-gallocyanin and basic proteins with picric acid-bromphenol blue or -eosin and a negative reaction for proteins with the fluorescent modification of the N-Bromosuccinimide-Schiff reaction. Acridine orange fluorochroming revealed a false positive reaction for DNA (green fluorescence) which was due to protein.