Development of extraction protocols for life detection biosensor-based instruments

Extraction experiments were performed to evaluate suitable sample-extraction and processing protocols that will be used by bioanalytical instruments like Life Marker Chip (LMC). These instruments will focus on the detection of molecules associated with life that will be extracted from the Martian soil. LMC is an antibody microarray biosensor instrument with optical readout, which uses fluorescently labeled antibodies, to detect and quantify the presence of polar and non-polar biomolecules, extracted from the Martian soil. The success of the LMC biomarkers detection experiment is dependent on the sample extraction protocol. The currently recommended extraction procedure, optimized for aliphatic biomarkers, consists in sonicating the samples using as solvent system 20:80 methanol:water with 1.5 mg mL−1 tween 80, which respects all the tight requirements associated with LMC biosensor. Examining this procedure for a particular class of biomarkers, the nucleobases adenine, cytosine, uracil and hypoxanthine adsorbed onto magnesium oxide (MgO), we observed low extraction efficiency, confirming that the selected solvent system is not able to extract with high efficiency aromatic biomarkers.