Schematic of RCA for SNP identification. An allele specific OCP anneals to the target sequence so that the 5' and 3' arms are adjacent to each other. The 3' terminal nucleotide of the OCP is at the SNP position. If it is complementary to the target, the OCP ends are covalently linked by a DNA ligase to form circles. The circles are then amplified in an ERCA reaction containing two primers, one of which is an Amplifluor containing a fluorophore and a non-fluorescent quencher as indicated. Incorporation of the primer into DNA product opens the primer hairpin giving a fluorescent signal.
Faruqi et al. BMC Genomics 2001 2:4 doi:10.1186/1471-2164-2-4