Figure 1.

Chemical Cleavage of Mismatch. * DNA strand was labeled with FAM or HEX at 5' and 3' ends respectively. Heteroduplex was formed by mixing equal amounts of wild-type and mutant DNA. Mismatched T.C on the heteroduplex was modified by KMnO₄ and hydroylamine and then cleaved by piperidine. A denaturing gel displays two cleavage fragments derived from both strands. Note: When only one of two reagents (either KMnO₄ or hydroxylamine) was applied on T.C mismatch, only one labeled cleavage fragment was detected by gel-electrophoresis – See Fig. 2 &3).