Fig. 2

Detection of BLV provirus in human blood and breast cancer tissue samples by short-fragment PCR. A Schematic representation of PCR amplification of short region of proviral gene in human samples. Numbers on the two sides of double arrow lines indicate the beginning and ending of the fragment amplified by PCR. The number under the double arrow line indicates the BLV proviral gene (LTR; gag; pol; env; tax and tax-3`LTR). B Electrophoresis result of PCR products. Each sample was tested in triplicate. Positive control (pc) DNA obtained from FLK-BLV cells was adjusted to BLV copy numbers of 100, 10, 5 and 1 copy in each PCR and amplified in duplicated. Distilled water was used as the negative control (nc). M indicates molecular weight marker (100 bp DNA ladder, (MIXELL Inc, Hiroshima, Japan)). C Summary of BVL detection in human samples by short range PCR. *The quality of DNA samples extracted from human samples were assessed by PCR amplification of human KRAS gene