Journal zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA of Virological Methods, 32 (1991) 4147 0 1991 Elsevier Science Publishers B.V. AD0VIS0168851091001080 41 VIRMET 01131 Reduction of vector contamination in detection of human papillomavirus DNA using full-length genomic DNA probes Sepehr N. Tabrizi, Anthony J. Borg and Suzanne M. Garland Microbiology Department. The Royal Women’s Hospital, Carlton, Victoria, Australia (Accepted 25 October 1990) Summary Nucleic acid hybridization techniques are currently the most specific and sensitive procedures available for diagnosing and typing human papillomavirus (HPV) infec- tion. HPV genomic DNA cloned into vector pBR322 or related vectors are commonly used as probes for detection of HPV. When isolating HPV insert DNA however, it is difficult to remove all pBR322 DNA. This can result in false positive readings when clinical specimens harbouring sequences homologous to pBR322 are screened. It was found that up to 200 ng of vector-like sequences in a clinical sample could be blocked by the addition of non-labelled, digested pBR322 sequences to the hybridization reac- tion. Human papillomavirus; Vector contamination; Vector sequence homology; Nucleic acid hybridization Introduction Human papillomaviruses (HPV) are the causative agents of common plantar warts and condyloma acuminata, and are strongly associated with genital dysplasias and malignant tumours (Dunn et al., 1968; Durst et al., 1983). Diagnosis of HPV by con- ventional virological techniques (Kingsbury et al., 1985) has been hampered by the inability to successfully propagate the virus in vitro, and sensitive serological tests are not yet available (Orth et al., 1978). Consequently the diagnosis of HPV infection has Correspondence to: S.N. Tabrizi, 132 Grattan St., Carlton, Victoria 3053, Australia. 0168.8510/91/$03.50