AN INTEGRATED SYSTEM FOR LABELING AND DETECTION OF BIOLOGICAL MOLECULES IN MARS ANALOG REGOLITH USING AN ANTIBODY MICROARRAY. J. Maule 1 , J.

Protein microarray analysis has had a major impact in modern biology and medicine by enabling detection of hundreds of proteins (and other molecules) using extremely small sample volumes [1-4]. Protein microarrays are printed on a glass slide using a robot and are only a few millimeters in diameter. Each consists of a grid of several hundred spots (100-200μm-diameter) of protein. Protein microarrays can be divided into two categories: target protein arrays [5] and antibody (Ab) microarrays [6]. Target protein microarrays have been used to study protein interactions with pharmaceutical drugs [7], enzyme substrates [8] and antibodies [9, 10]; the latter are examples of “antigen (Ag) microarrays”. Ab microarrays are arrays printed with antibodies, each of which binds to and recognizes a specific molecule termed the “antigen”. Some antibodies printed in a microarray format can detect antigens at concentrations below 1ng/ml [6]. Used most extensively for the analysis of human proteins in biomedical applications [11-15], this type of array has not been used for the detection of microbial or viral antigens in environmental samples [although microbial/viral antigen microarrays have been used for serodiagnosis [16]]. We have proposed that such a microbe-specific Ab microarray would provide a useful tool for in situ detection of biological molecules in space (due to its low mass, broad search capability and small sample required).