Figure 2

Comparison of screening methods in one ER-α A908G mutation-positive breast tumor from the CBCS. (a) Single-strand conformational polymorphism analysis of three Carolina Breast Cancer Study (CBCS) breast tumors, with the mutant band in tumor 622 indicated by an arrow. Tumors 615 and 617 contain only wild-type estrogen receptor (ER). (b) ³³P-cycle sequencing showing the A908G point mutation in CBCS breast tumor 622 (indicated by the arrow). (c) SNaPshot dideoxy primer extension analysis showing the wild-type (wt) and mutant (mut) ER peaks in both the 5' and 3' directions in CBCS breast tumor 622. Note that in the 5' direction the wild-type peak (A) is green and the mutant (G) is blue, whereas in the 3' direction, the wild-type peak (T) is red and the mutant (C) is black. (d) Big Dye terminator cycle sequencing analysis in the exon 4 region of ER-α surrounding codon 303 in CBCS breast tumor 622. Codon 303 is boxed; note that only the wild-type sequence (AAG) is observed.