Methods The ORF2 gene of TTV was amplified from the serum of a blood donor in Lanzhou region by nest PCR and inserted into vector pGEM-T then,after identification by DNA sequencing,subcloned to expression vector pET22b(+).

• 方法通过巢式PCR,从一份兰州地区无偿献血员血清中扩增TTV病毒的ORF2基因,并克隆到pGEM-T载体中,进行核苷酸序列分析。