The Quantitative Amplification Refractory Mutation System

The amplifi cation refractory mutation system (ARMS), which has also been described as allele-specifi c PCR (ASP) and PCR amplifi cation of specifi c alleles (PASA), is a PCR-based method of detecting single base mutations (Newton et al., 1989). ARMS has been applied successfully to the analysis of a wide range of polymorphisms, germline mutations and somatic mutations. The technique has the ability to discriminate low-levels of the mutant sequence in a high background of wild-type DNA (Billadeau et al., 1991). In an ARMS PCR the terminal 3'nucleotide of one of the PCR primers coincides with the target mutation. Most applications of the method rely on ‘end-point ̓ analysis, utilising the classic gel-electrophoresis method. However, end-point analysis can only assess the presence or absence of mutant or wild-type sequences and does not give an indication of the ratio of mutant to wild-type in a mixed population of DNA. Here we describe a real-time PCR adaptation of ARMS, quantitative ARMS, that allows measurement of the size of the population of each variant caister.com/pcrbooks