Abstract: Method for characterizing, classifying and differentiating tissues and cell types, for predicting the behavior of tissues and groups of cells, and for identifying genes with changed expression. The method involves obtaining genomic DNA from a tissue sample, the genomic DNA subsequently being subjected to shearing, cleaved by means of a restriction endonuclease or not treated by either one of these methods. The base cytosine, but not 5-methylcytosine, from the thus-obtained genomic DNA is then converted into uracil by treatment with a bisulfite solution. Fractions of the thus-treated genomic DNA are then amplified using either very short or degenerated oligonucleotides or oligonuclcotides which are complementary to adaptor oligonucleotides that have been ligated to the ends of the cleaved DNA.