SOLID2: An Antibody Array-Based Life-Detector Instrument in a Mars Drilling Simulation Experiment (MARTE)

摘要

A field prototype of an antibody array-based life-detector instrument, Signs Of LIfe Detector (SOLID2), hasbeen tested in a Mars drilling mission simulation called MARTE (Mars Astrobiology Research and TechnologyExperiment). As one of the analytical instruments on the MARTE robotic drilling rig, SOLID2 performed automaticsample processing and analysis of ground core samples (0.5 g) with protein microarrays that contained157 different antibodies. Core samples from different depths (down to 5.5 m) were analyzed, and positive reactionswere obtained in antibodies raised against the Gram-negative bacterium Leptospirillum ferrooxidans, aspecies of the genus Acidithiobacillus (both common microorganisms in the Río Tinto area), and extracts frombiofilms and other natural samples from the Río Tinto area. These positive reactions were absent when the sampleswere previously subjected to a high-temperature treatment, which indicates the biological origin and structuraldependency of the antibody-antigen reactions. We conclude that an antibody array-based life-detector instrumentlike SOLID2 can detect complex biological material, and it should be considered as a potentialanalytical instrument for future planetary missions that search for life.