| 摘要 |
A method for the detection of cytosine methylation in DNA samples is described. First, DNA is extracted from a sample and bound to a surface. In the second step, a genomic DNA sample is preferably treated with a bisulfite (=disulfite, hydrogen sulfite), such that all unmethylated cytosine bases are converted to uracil, while the 5-methylcytosine bases remain unchanged. In the third step of the method, one or more oligonucleotides is (are) hybridized to the treated DNA as primers. In the fourth step of the method, the hybridized primer(s) is or are elongated in a polymerase reaction. Here, labeled guanine nucleotides are preferably utilized which are essentially incorporated only if cytosine bases were still present in the treated DNA. Consequently, the extent of incorporation of guanine bases and thus also the number of incorporated labels is proportional to the methylation in the DNA sample under investigation. In the fifth step of the method, the labeled nucleotides that were not incorporated in the polymerase reaction are removed. In the sixth step of the method, the number of labels in the fragment generated by the primer extension is approximately determined by directly or indirectly measuring signal intensities emitted by these labels.
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