Figure 4.

(Opposite and above) Examples of combined SSCP/DA of seven different fragments of the BRCA1 and BRCA2 genes. Left and right panels show in magnification the duplex and SSCP portions of electrophoregrams, respectively. In addition, in the inset to (A), the real distance between duplex and SSCP portions is shown in a continuous fragment of electrophoregram. The peaks drawn with black and gray lines represent strands labeled with FAM or Tamra and with JOE or 6-carboxy-X-rhodamine (ROX), respectively. The shaded peaks represent fragments of the DNA size standard. Electrophoregrams of BRCA1 fragments spanning common polymorphism sites are shown (A–C). The electrophoregram representing homozygote for the more frequent polymorphic variant is shown in the upper panel, that representing the homozygote for the less frequent polymorphic variant in the lower panel, and that of the heterozygote is displayed in the central panel. Electrophoregrams of gene fragments spanning mutation or rare sequence variant sites are shown (D–G). In each case, the electrophoregrams representing the wild-type sequence or the common sequence variant (upper panel) are shown along with electrophoregrams representing the heterozygous sample (lower panel). Genotypes of the analyzed mutations, polymorphisms and variants are specified in each electrophoregram.