Suppression of Wild-Type Amplification by Selectivity Enhancing Agents in PCR Assays that Utilize SuperSelective Primers for the Detection of Rare Somatic Mutations

In PCR assays designed to detect rare somatic mutations, SuperSelective primers, by virtue of their short 3′-foot sequences, selectively initiate synthesis on mutant DNA target fragments, while suppressing the synthesis of related wild-type fragments, and the resulting threshold cycle reflects the quantity of mutant targets present. However, when there are ≤10 mutant target fragments in a sample, the threshold cycle that is observed occurs so late that it can be confused with the threshold cycle that arises from samples that contain only abundant related wild-type fragments.