Fig. 2

Sequence analysis of samples from six mixtures containing 0–100 % BRAF V600Emutation(+) cells. (a) Sequences of undigested products, TspRI (-): Where material was derived from 100 % A2058 cells (top panel) the mutant sequence, GAG, contributed approximately 50 % of the total, allowing clear categorization of sample as mutation (+). In all other cases (0–50 %, A2058 cells), it was difficult to judge whether the samples were mutation (+) or (-). (b) Sequences of digested products, TspRI (+): All samples containing the mutated (GAG) sequences demonstrated superior amplification of this in comparison to the wild type (GTG) after treatment with TspRI. The negative control containing 0 % A2058 cells (bottom panel) did not show amplification of the mutant sequence. Hence, the BRAF mutation could detected in samples containing as little as 5 % of A2058 cells (equating to 2.5 % of total DNA)