Figure 2: Double band on electrophoresis and double peaks on direct sequencing. a. A double band was observed on PCR electrophoresis of KIT exon 11 in 15 of 42 GIST cases. All of these double band samples are shown simultaneously on an agarose gel. The sample indicated by an arrow (Case 12) carried a duplicationtype insertion, and all of the other samples had a deletion-type mutation. b. Single base-pair double peaks, indicated by an arrow, on direct sequencing of the PCR product that showed a single band on electrophoresis. c. Superimposed consecutive double peaks, which appeared from the mutated location, on direct sequencing of the PCR product that showed a single band on electrophoresis. d. Superimposed consecutive double peaks, which appeared from the mutated location, on direct sequencing of the PCR product that showed a double band on electrophoresis.