Heidelberg 2006 – wissenschaftliches Programm
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EP: Extraterrestrische Physik
EP 19: Astrobiologie
EP 19.7: Fachvortrag
Donnerstag, 16. März 2006, 15:45–16:00, B
Life Marker Chip development for the European ExoMars mission: biosensor technology for life detection experiments on Mars — •Jan Toporski1, Mark Sims2, David Cullen3, and Andrew Steele4 — 1University of Kiel, Institute for Geosciences, Germany — 2University of Leicester, Space Research Centre, UK — 3ranfield University, Cranfield Biotechnology Centre, UK — 4Geophysical Laboratory, Carnegie Institution of Washington, USA
Numerous microbiological, molecular, and genetic techniques are being developed for a variety of biotechnology applications. One key area is the integration of nano-technology with biotechnology, resulting in the development of robust lab-on-a-chip instrumentation, which has application in many diverse and exciting fields. Specifically DNA and protein microarray technology is currently being considered for applications in space exploration. This technology, termed Life Marker Chip (LMC), has been identified as candidate analytical instrument for life detection experiments on Mars as part of the planned ESA ExoMars mission. The LMC instrument concept presented here is being developed and tested by two collaborating teams: SMILE (specific molecular identification of life experiment, lead by Mark Sims) and MASSE (modular assays for solar system exploration, lead by Andrew Steele).
DNA microarray technology is a DNA probe-based assay using short ssDNA fragments affixed to a solid substrate to identify microorganism and is capable of *fingerprinting* multiple microorganisms in one test. The basis of protein microarrays is the binding specificity of antibodies (capture molecule) to a specific antigen (target molecule). Each antibody is a protein that recognizes and non-covalently binds a specific three-dimensional structure (epitope) of an antigen. It can thus discriminate and detect a specific antigen in a complex sample that contains multiple different antigens. Microarray technology is integrated with microfluidic sample preparation systems for a start-to-finish automated instrument. In comparison to competing technologies for the detection of organics in solar system exploration, microarray-based analyses offer advantages such as the ability to obtain complex information on samples with high sensitivity and specificity. LMC technology is designed to detect a broad variety of compounds from fossil biomarkers to biological macromolecules and can thus produce information from the surface and shallow subsurface of Mars potentially much broader and detailed than previously considered techniques. Due to its flexibility and the potential to run thousands of specific reactions in parallel (first generation devices will limit detection to tens or hundreds of molecules), analysis can test for contaminants (during Earth to Mars transfer), traces of possible Martian life (past or present), or even evidence of Earth life that may have been transferred in the past.