| 摘要 |
Detecting 5-methylcytosine in a DNA sample, comprising adding a reagent to which methylated and non-methylated cytosines react differently, amplifying the DNA, hybridizing the product to a tagged oligonucleotide which is extended according to methylation status of the cytosine in the DNA, and detecting extended oligonucleotides, is new. Detecting 5-methylcytosine in a genomic DNA sample, comprising: (a) reacting the sample with a chemical reagent, where cytosine and 5-methylcytosine react differently so that after the reaction in the DNA duplex they show different base-pairing behavior; (b) amplifying the pretreated DNA using a polymerase and at least one oligonucleotide primer; (c) hybridizing the amplified sequence to at least one oligonucleotide to form a duplex whereby the 3' end of the oligonucleotide at least partly hybridizes to the DNA whose methylation is to be examined; (d) extending the 3' end of the oligonucleotide by at least one nucleotide at the 3' end if it is without a base pair partner, where the nucleotide caries a detectable marker, and extension is dependent on the methylation status of the respective cytosine in the sample DNA; and (e) detecting the extended oligonucleotide by detecting the marker. |
