Genotyping Using the TaqMan Assay

The 5'-nuclease allelic discrimination assay, or TaqMan assay, is a PCR-based assay for genotyping single nucleotide polymorphisms (SNPs). The region flanking the SNP is amplified in the presence of two allele-specific fluorescent probes. The probes do not fluoresce in solution because of a quencher at the 3' end. The presence of two probes allows the detection of both alleles in a single tube. Moreover, because probes are included in the PCR, genotypes are determined without any post-PCR processing, a feature that is unavailable with most other genotyping methods. This unit describes probe and primer design and PCR conditions.