Single-nucleotide polymorphisms (SNPs) emerge as a fundamental tool in personalized medicine due to their association with drug responses or disease predisposition. Single-base extension (SBE) is a common method for characterizing known SNPs, but involves complicated procedures or requires costly analytical instruments. Here, we describe a novel SNP genotyping based on SBE and enzyme-linked immunosorbent assay (ELISA). During the SBE, the 5' end fluorescein isothiocyanate-labeled allele-specific primer will extend with biotinylated dideoxynucleotides which are complementary to the SNP sites. The extension product will then be captured by streptavidin-coated nanoparticle and develop blue color in the ELISA assay. We validated this method by detecting SNPs for TP53 gene codon 273 from 68 individuals and the data were 100% in concordant with DNA sequencing. Thus, SBE and ELISA-based SNPs assay is a simple and accurate method for SNP genotyping.