Cytochemistry of Virus-Induced Inclusions Containing Nucleic Acids 1

Abstract

Summary

Cytoplasmic inclusions produced by reovirus, type 3, contain RNA that is stainable by 4 TBM methods, by dilute toluidine blue after nitrosation and by pyronin. Staining of inclusions by all these methods, except for TBM, method C, is due to the presence of single-stranded RNA which is susceptible to digestion by RNase. Double-stranded RNA is partially responsible for staining by TBM, method C, since staining is reduced but not abolished by digestion with RNase. Hydrolysis of RNA by hot TCA prevents all staining by these methods. The ability of the reovirus inclusion to stain green with acridine orange is unaffected by all methods that remove nucleic acids demonstrable by other methods and is probably due to dye-binding by protein. The results of digestion by combinations of nucleases and pepsin are variable, irreproducible and incapable of logical interpretation.