When
3:30 p.m., March 25, 2008
Where
Kuiper Space Sciences Building 308
Dr. Linda Powers, professor, Electrical and Computer Engineering, University of Arizona, is the scheduled speaker.
Abstract
Using a unique combination of leading-edge technologies, we have developed a hand-held, continuous, real-time monitor for detection of microbes, together with microbe capture technology for identification. Together these are capable of statistically sampling the environment for microbes [including bacteria, fungi, spores and viruses] and exotoxins, identifying the specific microbes, and determining cell viability. This system is sensitive enough to detect very low levels [~20 cells/cm2 on surfaces or ~100 cells/50 mL solution] of microbes in minutes. Detection of microbes is based upon intrinsic fluorescence of the cells and spores such as that from metabolites, amino acids, and other specific cell components. The multi-wavelength fluorescence detection device requires no reagents or sample contact and distinguishes viable cells, non-viable cells, and spores. Remote, realtime detection and quantification of live cells, dead cells, and spores on rock, soil, and ice surfaces and subsurfaces or in water at low concentrations of unknown organism types [~10] is pivotal in the search for extraterrestrial life. Characterization of limits of life on rock, soil, and ice surfaces and subsurfaces and in water from earth analogs also provides clues regarding what organisms survive space-like conditions. We have developed such a portable field unit and tested it with studies of Mars-like environments on earth, with the NASA Spaceward Bound Program, that are used as analogs for science and technology development for future Mars missions.
The microbe capture technology which provides identification is based on molecular recognition of pathogenesis using iron acquisition and eukaryotic receptor adhesion strategies as well as peptide ligands produced by combinatorial chemistry methods. These non-antibody-based ligands are tethered to the sensor in a patterned array and statistically sample the environment. Pathogen identification is made based on which ligands are bound by microbes. Furthermore, these capture technology sensors can also be used for culture and other classical microbiological identification methods [e.g., PCR, ELISA].
Abstract
Using a unique combination of leading-edge technologies, we have developed a hand-held, continuous, real-time monitor for detection of microbes, together with microbe capture technology for identification. Together these are capable of statistically sampling the environment for microbes [including bacteria, fungi, spores and viruses] and exotoxins, identifying the specific microbes, and determining cell viability. This system is sensitive enough to detect very low levels [~20 cells/cm2 on surfaces or ~100 cells/50 mL solution] of microbes in minutes. Detection of microbes is based upon intrinsic fluorescence of the cells and spores such as that from metabolites, amino acids, and other specific cell components. The multi-wavelength fluorescence detection device requires no reagents or sample contact and distinguishes viable cells, non-viable cells, and spores. Remote, realtime detection and quantification of live cells, dead cells, and spores on rock, soil, and ice surfaces and subsurfaces or in water at low concentrations of unknown organism types [~10] is pivotal in the search for extraterrestrial life. Characterization of limits of life on rock, soil, and ice surfaces and subsurfaces and in water from earth analogs also provides clues regarding what organisms survive space-like conditions. We have developed such a portable field unit and tested it with studies of Mars-like environments on earth, with the NASA Spaceward Bound Program, that are used as analogs for science and technology development for future Mars missions.
The microbe capture technology which provides identification is based on molecular recognition of pathogenesis using iron acquisition and eukaryotic receptor adhesion strategies as well as peptide ligands produced by combinatorial chemistry methods. These non-antibody-based ligands are tethered to the sensor in a patterned array and statistically sample the environment. Pathogen identification is made based on which ligands are bound by microbes. Furthermore, these capture technology sensors can also be used for culture and other classical microbiological identification methods [e.g., PCR, ELISA].
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