DGGE follow-up of a CML patient treated successively by imatinib and dasatinib. A DGGE restricted to BCR-ABL RT-PCR fragments was performed for the patient (lanes 3-6), an unmutated control (lanes 2 and 7) and a V379I heterozygous mutated control (lane 1). Concerning the patient, the treatment, its duration, and the BCR-ABL/ABL ratio are shown. For each experiment, direct sequencing characterizes the BCR-ABL alleles. Letters in the DGGE profile indicate the homoduplex bands corresponding respectively to the BCR-ABL unmutated allele (a), the V379I BCR-ABL allele (b), and the V379I + T315I BCR-ABL allele (c). The asterisks (^* and ^**) indicate the heteroduplexes, characteristics of the presence of 2 homoduplexes.