Patent ID: 7524629

Claim:
A method for concurrently detecting 5-methylcytosine and SNP in genomic DNA samples, characterized in that the following steps are carried out: (a) chemically converting a genomic DNA from a DNA sample with a reagent, 5-methylcytosine and cytosine reacting differently, thus exhibiting different base pairing behaviors in the DNA duplex subsequent to the reaction; (b) amplifying the pretreated DNA using a polymerase and at least one oligonucleotide (type A) as a primer; (c) hybridizing the amplified genomic DNA to at least one oligonucleotide (type B), forming a duplex, said hybridized oligonucleotides of type B, with their 3′-ends, immediately or at a distance of up to 10 bases, adjoining the positions to be analyzed with regard to their methylation in the genomic DNA sample; (d) elongating the oligonucleotide (type B) having a known sequence of n nucleotides by means of a polymerase by a plurality of nucleotides, at least one nucleotide carrying a detectable label, and the elongation depending on the methylation status of the specific cytosine in the genomic DNA sample and on a single nucleotide polymorphism; (e) analyzing the elongated oligonucleotides for the presence of the label; and (f) deducing the presence of said 5-methylcytosine and SNP in the genomic DNA samples from the incorporated label.