Automation of chemosensitivity testing - Enabling personalized cancer therapy

Cell based assays are obtaining greater importance in a plurality of scientific research fields. Due to their high sensitivity towards a great variety of input factors, these assays are also increasingly used in biochemical research, pharmacological drug screening and medical diagnostics. For cancer treatment, cellular assays can play a key role to the individualisation of chemotherapy, as different possible drugs can be tested with cells or tissue of a specific patient before commencing the treatment. Combining cellular assays with laboratory automation equipment like liquid handling systems is the key to large scale chemosensitivity-testing of tumour cells. Therefore our research group has developed an automated high-content online measurement system for cell based assays. The system is comprised of a pipetting robot, sensors for measurement of pH, pO₂, electric signals and cell adhesion, a digital microscope and a climate chamber. The robot is used to supply the cells with nutrient solution or active agents that are to be tested, while the sensors monitor the acidification of the medium, the uptake of oxygen and the adhesion of the cells to the substrate. Reflected light as well as fluorescence imaging during the course of an experiment are possible due to the included microscope. Cells and sensors are arranged in a special 24-well micro plate that is placed at a fixed position within the system. Oxygen and pH values are usually measured every 5 to 15 seconds. The running software also allows planning of experiments over a long period of time (several days to weeks). Furthermore, this paper shows proof of principle measurements with human cancer cells (MCF-7) treated with different chemotherapeutic agents in different concentrations. Hence, the feasibility of the working principle could be shown, although the statistical correlation of in-vitro and in-vivo results still has to be proven in clinical trials.