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Project Progress

Our major objective and one of the objectives of the Astrobiology roadmap is “Biosignatures to be sought in Solar System materials search for signs of life in the Solar System and beyond”. We are developing techniques which can be used for direct in situ measurements on future missions.

In addition to our goal of linking lipopolysaccharide (LPS) to an antigen and subsequent detection by Limulus Amebocyte Lysate (LAL), we extended our technique to amplify the detection of biosignatures using an enzyme labeled monoclonal antibody to a model antigen. This is compatible with our existing prototype instrument design to collect kinetic spectrophotometric data from competitive labeled antibody assays.

We have demonstrated feasibility of immobilizing our test antigen (insulin) to the plastic surface and binding of the enzyme labeled monoclonal to the immobilized antigen, shown in Figure 1A. Our portable reader will quantify that signal which does not bind as proportional to the amount of antigen in the sample (Figure 1B).

Through collaboration with Andrew Steele, Carnegie Institution of Washington (CIW) Astrobiology Center, we have incorporated protein microarrays (Figure 1C) to our assay format. This will significantly impact our work by enabling simultaneous detection of up to 50 different antigens per test. Currently our portable reader will accommodate 4 tests, or 200 potential biosignature targets. Part of that collaboration was a study of the immunological detection of biosignatures extracted from JSC Mars-1 simulant regolith (paper submitted to Astrobiology). These observations demonstrate the practicality of microarray immunoassay for in situ detection of biological molecules in environmental samples, including martian regolith.

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