'Dynamic allele-specific hybridization'.

This technique is based on differences in temperatures between duplexes resulting due to perfect match and mismatch between the PCR product and an oligonucleotide, 15-21 bases long.

The PCR product is immobilized on a solid support and denatured to give single stranded DNA, which is then hybridized to an oligonucleotide probe containing the SNP site.

The duplex formed is detected by an intercalating fluorescent dye, specific for double stranded DNA.

When increasing temperature denatures this hybrid duplex, the melting can be followed by the reduction in the fluorescence,

which depends upon the relative proportion of duplex DNA and single stranded DNAs.

A rapid and sudden fall in fluorescence will indicate Till' and a dramatic fall in T m will suggest a mismatch, thus identifying the SNP.