A 30-year old patient (NB) had persistent positive "high-risk" HPV hc2 assays in spite of negative Pap cytology findings 3 years after a cone biopsy which confirmed a CIN3/2 lesion with HPV-52 DNA isolated from the archived paraffin-embedded tissue. The electropherogram of DNA sequencing on a recent liquid-based cytology sample shows an ambiguous tracing (upper tracing). However, using a second nested PCR product as the template for sequencing reaction, the base-calling peaks (lower tracing) can be deciphered. Alignment of the complementary sequence in reading frame spaced as amino acid codons compared to nucleotides 6727–6798 of GenBank Locus AJ400628 is as follows: 5' aat ggt att tgc tgg ttt aat caa ttg ttt gtt aca gtt gtg gat acc act a ga agt acc aat ttt act att Sample NB. 5' aat ggt att tgc tgg ttt aat cag ttg ttt gta acg gtt gtt gat act act cgc agt acc aat ttt act att AJ400628. Although the sequence of sample NB has a mismatch of 7 bases (underlined) against those of an HPV-87 prototype, the amino acid sequence, NGICWFNQLFVTVVDTTRSTNFTI, coded by both nucleotides is identical in this segment.