BMC Cancer 2008, 8:59 http://www.biomedcentral.com/1471-2407/8/59 FDiigffuereen1ce plot showing different mutations relative to the wild type controls Difference plot showing different mutations relative to the wild type controls. In difference plots, the melting profile of a wild type control is chosen as a horizontal base line and the relative differences in the melting of all the other samples are plotted relative to this baseline. The figure shows difference plots for each of the 3 exons containing one of the common Ashkenazi mutations (185delAG, 5382insC and 6174delT). Each trace represents the amplicon from a different individual's DNA sample. All mutations were clearly distinct from the wild type controls. a. BRCA1 exon 2: Melt curves of each mutation (pink: 188del11, red: 185delAG and green: 185insA) were plotted against the wild type (blue). b. BRCA1 exon 20: Melt curves of each mutation (pink: 5396+1G>A, red: 5331G>A and green: 5382insC) were plotted against melt curve of the wild type (blue). c. BRCA2 exon 11: Melt curves of each mutation (pink: 6024delTA, red: 6293C>G and green: 6174delT) were plotted against melt curve of the wild type (blue). Page 4 of 7 (page number not for citation purposes)