Patent ID: 7037650

Claim:
A method for determining DNA methylation status at a cytosine residue of a CpG sequence, comprising the steps of: (a) obtaining genomic DNA from a DNA sample to be assayed; (b) reacting the genomic DNA with sodium bisulfite to convert unmethylated cytosine residues to uracil residues while leaving any 5-methylcytosine residues unchanged to create an exposed bisulfite-converted DNA sample having binding sites for primers specific for the bisulfite-converted DNA sample; (c) performing a PCR amplification procedure using top strand or bottom strand specific primers; (d) isolating the PCR amplification products; (e) performing a primer extension reaction using a Ms-SNuPE primer, dNTPs and Taq polymerase, wherein the Ms-SNuPE primer comprises from about a 15-mer to about a 22-mer length primer sequence that is complementary to the bisulfite-converted DNA sample and terminates immediately 5′ of the cytosine residue of the CpG sequence to be assayed; and (f) determining the methylation state at the cytosine residue of the CpG sequence by determining the identity of the first primer-extended base.