A polymerase chain reaction (PCR) investigation of oral verrucae which contain HPV types 2 and 57 by in situ hybridization

Abstract

The polymerase chain reaction (PCR) and direct DNA sequencing have been used to identify strain variants of HPV types 2a/57 in formalin‐fixed sections of human oral verrucae, where the virus had previously been detected by both immunofluorescence and in situ hybridization. By employing type‐specific and type‐common PCR primers we show that these lesions contain a mixture of viral DNAs which vary by up to 27% in DNA sequence, in a region where the variation between HPV types 2a and 57 is only 4%. The extra discriminatory power of fluorescent sequencing indicates that the lesions may also contain wild‐type HPV2a/57 DNA which could provide a helper function for defective viral DNA molecules or indicate a mosaic origin for the lesions.