Molecular Oncology group uses high-density DNA arrays to generate expression profiles of tumor tissue and cell lines. We use the system of Affymetrix (Santa Clara, USA), in which gene specific oligonucleotides are synthesized directly on a glass surface (Lipshutz et al. Nature Genet. 21:20-24, 1999). State of the art expression arrays allow the simultaneous analysis of all human genes (approx. 20,000 genes) on a single DNA array.
In the hybridization oven, the labeled RNA probe of the target tissue is hybridized overnight to the spotted oligonucleotides of the "gene chip". In the washing station ("Fluidics"), DNA arrays are rigorously and precisely washed according to a computer-controlled program before the specific hybridization signal is read out by means of a high-resolution scanner (not visible here).
A typical Affymetrix DNA Array (gene chip) can be seen here.
DNA array (gene chip) consisting of the actual array (glass surface in the middle) and the so-called cartridge, in which the hybridization solution is filled via septa on the reverse side.