Figure 2.

Discrimination between WT and mutant PCR products by MBs. Separate PCR products (n = 10), each generated from ≈50 genome equivalents of DNA of cells containing the indicated mutations of c-Ki-Ras, were analyzed with the MB probes described above. Representative examples of the PCR products used for MB analysis were purified and sequenced directly. In the cases with Gly12Cys and Gly12Arg mutations, contaminating nonneoplastic cells within the tumor presumably accounted for the relatively low ratios. In the cases with Gly12Ser and Gly12Asp, there were apparently two or more alleles of mutant c-Ki-Ras for every WT allele; both these tumors were aneuploid.