We amplified various amounts of DNA derived from frozen SF210 and U251NCI human glioblastoma cells, carried out comparative genomic hybridization (CGH) using degenerate oligonucleotide primed-PCR (DOP-PCR) products as test probes, and compared results to analyses performed with probes prepared by standard nick translation. Next we extracted DNA from hematoxylin-eosin (HE)- and methyl green (MG)-stained, microdissected sections of formalin-fixed and paraffin-embedded U251NCI cells, amplified and labeled it by DOP-PCR, and subjected it to CGH. Finally, we used the same methods in multiple samples from a single human mixed glioma tissue. DOP-PCR products from 50 pg to 250 ng of DNA were equally effective in generating the same CGH profiles as the standard method. DOP-PCR products from microdissected pieces of MG-stained cells were effective probes for CGH, but HE-stained samples were not desirable. As the proportion of HE-stained sample increased, CGH profiles deteriorated. DOP-PCR products from microdissected pieces of MG-stained paraffin sections of glioma tissue produced CGH profiles compatible with their histological features. CGH performed with DOP-PCR products from microdissected paraffin blocks allows for the accurate investigation of the cytogenetic characteristics from invasive tumors and of cytogenetic heterogeneity within neoplastic tissue.