Reduction of genome information from a single cell into a genome profile. Successive random PCR, in which the product of one round of random PCR was used as the template for the next session of random PCR, was carried out. Note that primer binding occurs in a mismatch-containing structure in this relaxed mode of PCR (random PCR), thus enabling us to sample DNA fragments from various sites of the genome. In TGGE, DNA fragments layered on the top of a slab gel migrate downward in a horizontal line with a characteristic curvature caused by the temperature gradient. Featuring point(s) of each DNA fragment are assigned and processed to generate species identification dots (spiddos) with a computer. The PaSS (pattern similarity score) calculation is performed as described in the text.