Tissue microdissection and degenerate oligonucleotide primed-polymerase chain reaction (DOP-PCR) is an effective method to analyze genetic aberrations in invasive tumors

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.