RFLP analysis of JAK2 V617F mutation. (A) PCR amplification of JAK2: Lane M, 100-bp ladder; Lane 1 negative control without template, lanes 3–13, samples from patients, lane 2 normal control (K562 cell line), and lane 14 mutant control (HEL cell line). Arrow indicates the size of the amplified products. (B) BsaXI digestion: Lane M, 100-bp ladder; Lane 1 negative control without template, lanes 2 normal control (K562 cell line), lane 3,4, 9 and 13 samples from patients with a mixed pattern of both mutant and wild-type alleles, and lane 5–7 and 10–12 samples from patients with wildtype allele, and lane 14 is the mutant control (HEL cell line).