Working Group Stahl - Micorarray technologies and Biotesting
In the ‘post-genome era’ - as the human genome project has come to completion - whole-genome studies are becoming more and more important as the amount of DNA sequences available to researchers has been rising exponentially. For the understanding of biological systems with up to 30,000 genes the measurement of mRNA levels for a complete set of transcripts of an organism will be necessary. An ideal tool for such measurements is the DNA microarray or so-called DNA chip technology, a high-throughput method that have become a standard tool for gene expression profiling as the mRNA levels of a large number of genes can be measured in a single assay. This is the great advantage over traditional methods for gene expression analysis such as RT-PCR, northern blotting or more abvanced techniques such as differential display which have also enabled the discovery of novel differentially expressed genes. However, only few samples can be analyzed simultaneously using these well-established methods. While conventional methods are confining themselves to the examination of single genes, a DNA chip experiment delivers a complete gene expressions pattern of the cell.
Today it is import to understand the potential risk that new materials pose to humans e.g. in regenerative medicine or tissue engineering applications because a wide range of new materials like nanoparticles of different types and different properties are synthesized which need to be examined concerning their toxicity. As a constantly increasing amount of technological products become available to the customers, concerns have been raised regarding the harm and the potential health risk of these products. For this reason we have developed a new cell based iterative in-vitro testing system to examine all kind of materials, biomolecules and nanoparticles towards their toxicity. Within our screening system different fluorescent dyes can be used to measure biological processes like active metabolism (indicating cell viability), DNA staining (indicating proliferation), the production of reactive oxygen species (indicating cellular stress) as well as gene expression. Concentrating on the possible adsorption of the nanoparticle into the human organism, via skin and via respiratory tract, the effects on different cell lines and human stem cells can be examined.