On a worldwide basis, cervical carcinoma is one of the most frequent tumor-related causes of death in women. Substantially responsible for the development of cervical carcinoma is a persistent infection with human papillo-ma viruses (HPV) of the “high-risk type”. A method for detection of such HPV infections in fixed tissue sections is provided by the ZytoFast® HPV-ISH system which is based on the method of chromogenic in situ hybridization (CISH). This study examined the suitability of the Eppendorf Thermomixer comfort and the Eppendorf ThermoStat plus with slide adapter for in situ hybridization in HPV diagnostics. It was shown that Thermomixer comfort and ThermoStat plus yield comparable results with regard to signal intensity and unspecific background as does the standard method with a heating plate and incubator. Moreover, because of the digitally programmable tempera-ture steps, Thermomixer comfort and ThermoStat plus facilitate maximum reproducibility of the experimental conditions and require substantially less effort.

Fluorescence in situ hybridization (FISH) is the gold standard methodology for gene copy number determination in cultured cells, metaphase spreads, tissue samples or cytologic specimens. While it has primarily been used as a research tool during the last decade, there is a growing demand for the use of FISH as a diagnostic tool. In such a setting, analysis speed, reliability and cost efficiency become important parameters. Perhaps the most critical step in the FISH procedure is the proper adjustment and maintenance of temperatures for DNA denaturation and probe hybridization. We have compared different devices for slide heating to estimate their suitability for FISH analysis. Our study demonstrates that programmable slide incubators are profoundly superior to the classical waterbath for FISH analysis. The Eppendorf add-on hybridization station is an attractive alternative for owners of the Thermomixer comfort device that allows for high-quality FISH analysis at low cost for machinery.

The incubation steps during cDNA synthesis, in vitro transcription reaction, and target fragmentation were performed using the Hybex Microarray Incubation System (SciGene) and Eppendorf ThermoStat plus instruments. Hybridization, washing, staining, and scanning protocols, respectively, were performed on Affymetrix GeneChip instruments (Hybridization Oven 640, Fluidics Station FS450, Scanner GCS3000) as… …