The identification of mutations is very important in such aspects of molecular biology as medical diagnostics, ascertaining structure/function relationships, population genetic studies, and in confirming the authenticity of new candidate genes. Presently there are a variety of different techniques used to identify somatic and germline mutations. In some instances, gross genetic alterations are best characterized by cytogenetic analysis, FISH, or by Southern blot. However, in most cases the underlying mutations are too subtle to be revealed by these techniques and are best characterized by examination of PCR products generated from putative disease alleles. While there are over a dozen different methods to screen for mutant alleles in PCR products, no technique is absolutely sensitive and each has specific advantages and disadvantages in its ability to detect unknown mutations.