Accommodation of Experiment Conditions for the Space Experiment „Cellular Responses to Radiation in Space“

In the current work, preparatory experiments for the Space Experiment “Cellular Responses to Radiation in Space” that will be accomplished in the Biolab of the laboratory module Columbus on the International Space Station (ISS) were performed. This experiment will analyse the effects of combined radiation and microgravity effects on the behaviour of human cells, especially in respect to DNA damage and repair and activation of the NF-κB pathway. It was necessary to test the biological activity of the designated radiation source Promethium-147 regarding cell survival and NF-κB activation, in both points an agreement with the postulated qualities was reached. The experimental hardware consisting of microtiter plate units and fluid reservoirs has been tested and several aspects that have to be improved have been identified. Furthermore the evaluation of a suitable cytotoxicity test system as well as the testing of a possible method for analyzing the cells after return to earth was conducted. It turned out that there are more experiments necessary to find a suitable test system. After fixation of the cells for termination of the experiment, several procedures are earmarked. The green fluorescence of the reporter cell line HEK-pNF-κBd2EGFP/ Neo L2 will be detected by fluorescence microscopy or flow cytometry. The fixed cell layers will be subjected to immunfluorescence staining. After optimization of the conditions, the method of γH2AX immunofluorescence can be used for analysis of DNA double-strand breaks and their repair