Oligonucleotide Ligation Assay (OLA) for SNP Genotyping

Oligonucleotide ligation assay (OLA) is a rapid, sensitive, and specific method for the detection of known single nucleotide polymorphisms (SNPs). This method is based on the joining of two adjacent oligonucleotide probes (Capture and Reporter Oligos) using a DNA ligase while they are annealed to a complementary DNA target (e.g. PCR product).

In our laboratory, the capture probes are fluorescently labeled and genotype-specific. Typically, there are two capture probes for each allele. These two probes differ only in sequence at the last base at the 3' end. The reporter probe is a common probe that is complementary to the target DNA sequence immediately downstream (3') of the SNP site. This probe is modified with a phosphate at its 5' end, and has no fluorescent modification. Allele discrimination occurs by the ability of DNA ligase to join perfectly matched probes; a 3' mismatch in the capture probe will prevent ligation. The OLA process is illustrated below.

You may browse our growing list of currently available SNP assays. New SNP assays can be designed upon request.