With the completion of the human genome project, single-nucleotide polymorphisms (SNPs) have become the focus of intense study in biomedical research. Polymerase-mediated primer extension has been employed in a variety of SNP assays. However, these SNP assays using polymerase without proofreading function are compromised by their low reliability. Using a newly developed short amplicon harboring restriction enzyme site, EcoR-I, we were able to compare the single-base discrimination abilities of polymerases with and without proofreading function ...