Genotyping of HPV
HPV genotyping was performed with Type-specific HPV genotyping kit (Bioperfectus Ltd, Jiangsu, P.R. China). After vials for HPV genotyping were transported to the HPV laboratory of Gy&Ob hospital of Fudan University, a qualitative in vitro assay was performed to detect the result for HPV16, HPV18 and other 12 HPV genotypes, including HPV31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66 and 68.