Figure 3: Gel electrophoresis of polymerase chain reaction product for the infants aged 9 to 12 months. Number 1 is a negative control of PCR, numbers 2, 3, 4, 6, 7, and 8 are HTLV1-positive samples which showed 222 bp and 149 bp fragments of HTLV1 LTR and human TATA-binding protein (internal control of PCR) genes, respectively. Number 5 is a 100 bp DNA size marker, and number 9 is a positive control of PCR.