DETECTION OF MUTATIONS BY CLEAVAGE OF DNA HETERODUPLEXES WITH BACTERIOPHAGE RESOLVASES

We have explored the application of the bacteriophage resolvases T4 en donuclease VII and T7 endonuclease I for detecting mutations in genomi c DNA. Heteroduplex DNA fragments prepared by amplification from DNA c ontaining known mutations were cleaved by one or both enzymes at nucle otide mismatches created by 3 of 3 short deletions and 13 of 14 point mutations in fragments as large as 940 basepairs. Heteroduplexes repre senting all four classes of possible single nucleotide mismatches were cleaved, and the sizes of the cleavage products generated correlated with the location of the mutation. We conclude that bacteriophage reso lvases may be useful reagents for the rapid screening of DNA for mutat ions.