A rapid simple in situ hybridization method for herpes simplex virus employing a synthetic biotin-labeled oligonucleotide probe: a comparison with immunohistochemical methods for HSV detection.

We examined 28 paraffin-embedded tissue specimens with histologic evidence of herpes virus infection by in situ hybridization (ISH) utilizing manual capillary action technology (MicroProbe Staining System) and a 21 base synthetic multibiotinylated oligonucleotide probe from the HSV glycoprotein C region. The results were compared to a rapid simple immunohistochemical (IHC) protocol for detection of HSV proteins. HSV was detected by ISH and IHC in all but one specimen which was shown to be positive for varicella zoster virus by direct fluorescent antibody studies. Hybridization signal was confined to the nucleus in all cases. Staining was identified in cells with early as well as late cytopathic effect. IHC produced intense nuclear and/or cytoplasmic signal in infected cells and stained in areas of necrosis which were otherwise spared by ISH. HSV was detected by IHC and/or ISH in 3/5 specimens with histology suggestive of, but not diagnostic for, HSV infection. Both techniques were sensitive and specific for HSV, resulted in rapid detection of the pathogen in routinely processed tissues, and may be useful in cases where the histologic impression is equivocal for HSV infection. ISH for HSV may be preferred because it can identify early HSV infection, which in turn can be treated with antiviral agents.