Gel electrophoresis pattern of HR-HPV types (16/31/33 and 35). (A) and (B) are representative gel electrophoresis patterns of the analysis for HR-HPV types of breast tissue. Samples: (A) loading marker = 100 bp plus DNA ladder (100 bp–3000 bp), HPV positive controls = HPV16 (325 bp), HPV31 (520 bp), HPV33 (227 bp) and HPV35 (280 bp) respectively; ID66, 68 and 69 = HPV negative clinical sample, ID67 = HPV positive clinical sample, positive control (C+) = internal control, human DNA (β-globin 723 bp), negative control (C-); (B) loading marker = 100 bp plus DNA ladder (100 bp–3000 bp), HPV positive controls = HPV16 (325 bp), HPV31 (520 bp), HPV33 (227 bp) and HPV35 (280 bp) respectively; ID109, 111, 112, 114, and 115 = HPV negative clinical sample, ID110, 113 = HPV positive clinical sample, ID116 = absent internal control (β-globin 723 bp) indicating inadequate quality of sample; positive control (C+) = internal control, human DNA (β-globin 723 bp), negative control (C-).