The experiment ,,Phage and Uracil response" (PUR) will be accomodated in the EXPOSE facility of the International Space Station (ISS) and its main goal to examine and quantify the effect of specific space parameters on nucleic acid models. To achive this an improved method for the preparation of good quality DNA and bacteriophage thin films was elaborated and the homogenity of the films were controlled by UV spectroscopy and microscopy. To provide experimental evidence for the hypothesis that interplanetary transfer of life is possible, phage T7 and isolated T7 DNA thin films have been exposed to simulated space conditions: high vacuum (10~(-4) Pa), temperature fluctuations, intense UVC (? = 254 nm) as well as simulated extraterrestrial solar radiation (> 200 nm). The effects on DNA hydration, conformation and packing of DNA/ phage damage were examined. Characteristic changes in the UV absorption spectrum, in the elecrrophoretic pattern of DNA/phage and the decrease of the amount of PCR products have been detected indicating the damage of isolated and intraphage T7 DNA.
展开▼
