Molecular assay for rapid identification and characterization of JAK2 V617F mutation. (A) Electrophoretogram of AS-PCR for JAK2 V617F mutation in MDS/MPD-Unclassifiable disease. In a healthy patient with the wild-type G/G genotype, only a single 364-bp band is visible (lane 9). A point mutation V617F G→T (either G/T or T/T) is indicated by the presence of a second 203-bp band. Lanes 1-2, MDS/MPD-U; lanes 3-6, RARS-T; lane 7, AML; lane 8, CMML-1; lane 9, normal negative control; lane 10, CIMF (T/T genotype) positive control. (B) Partial sequence of JAK2 exon 14 showing wild-type (G/G) sequence in a healthy patient (middle) and mutated (G/T or T/T) sequences in patient with MDS/MPD-U (right) and CIMF (left). (C) LightTyper DNA melting curves: wild type (middle) is characterized by a single peak (higher melting temperature), G/T genotype (left) by 2 peaks, and T/T genotype (right) by one peak (lower melting temperature).