Sequencing experiments. Each peak on electropherograms represents one base (green indicates A; red, T; blue, C; and black, G). The wild-type sequence is indicated at the top. All experiments were performed from biologic samples obtained from the same patient (no. 655). For each, the nucleotides around position 771 and the 825 to 869 segment are shown. Each experiment is identified by the nature of the biologic sample (LN indicates lymph node; PB, peripheral blood; and BM, bone marrow) and by the time from diagnosis at which it was obtained (diag). The 771G>A mutation, shared by all samples, shows the clonality of the disease. From the 3 later samples, where different subclones dominate, it can be deduced that the 771G>A mutation was acquired first, followed by the 849del and by the 830A>G. The last example shows that the sensitivity of the technique allows for the detection of minor subclones.