A comparison of commercially available probes for in situ hybridization to human papillomavirus DNA

Several commercially prepared DNA probes to human papillomavirus are available for nonisotopic in situ hybridization. Our laboratory conducted a comparison of eight commercially available DNA probes for diagnostic purposes. Six type-specific and two wide-spectrum probes from two vendors (Enzo and Digene Diagnostics) were used on routinely processed, formalin-fixed, paraffin-embedded tissue sections. An additional wide-spectrum probe from Dako was also investigated, but testing was discontinued early because performance was unsatisfactory. An automated apparatus was used for this comparison study, and the protocols for the kits were adapted accordingly. Twenty-four cases were studied; these included four cases of normal cervical tissue, six cases of condyloma, six cases of mild (low-grade) dysplasia with condyloma, five cases of moderate to severe (high-grade) dysplasia, and three cases of carcinoma. All of the low-grade dysplasias and the condyloma hybridized with at least one wide-spectrum and one type-specific probe. By contrast, only half of the high-grade dysplasias and carcinomas hybridized to any probe. The results of hybridizing with the type-specific probes were equivocal. Four cases reacted with two different type-specific probes. We conclude that nonisotopic in situ hybridization is a reproducible technique for detection of human papillomavirus, and recommend this method as an adjunct for routine histology in equivocal cases of condyloma. The technique adapts to a mechanized system, increasing its utility in the clinical setting. In our laboratory, the Enzo wide-spectrum probe was easier to interpret, generating a stronger signal with less nonspecific binding of chromogen. The sensitivities of the probes tested were not significantly different.(ABSTRACT TRUNCATED AT 250 WORDS)