The present invention relates to a method for selectively amplifying non-methylated sequences of a DNA comprising the steps of (i) providing a sample comprising a DNA which is methylated at least one site, (ii) treating the DNA in the sample with a methylation-dependent nuclease, and (iii) amplifying the DNA cut using the methylation-dependent nuclease. In addition, the invention relates to kits for use in the method according to the invention. The method according to the invention can be used for selectively preparing to (selectively accumulating) non-methylated sequence segments of genomic DNA and for analysing the global methylation pattern in genomic DNA.