NASA SBIR 2004 Solicitation


PROPOSAL NUMBER: 04 S4.05-9355
SUBTOPIC TITLE: Astrobiology
PROPOSAL TITLE: An Instrument for Detecting Protein Expression under Radiation and Microgravity

SMALL BUSINESS CONCERN (Name, E-mail, Mail Address, City/State/Zip, Phone)
Radiation Monitoring Devices, Inc.
44 Hunt St
Watertown, MA 02472-4699

PRINCIPAL INVESTIGATOR/PROJECT MANAGER (Name, E-mail, Mail Address, City/State/Zip, Phone)
Louis Strong
44 Hunt St
Watertown, MA 02472-4699

An understanding of the basic cellular mechanisms organisms use to cope with extreme environments is important as we search for life in other parts of the universe and seek to adapt terrestrial life beyond earth. Radiation Monitoring Devices, Inc. proposes to build an automated, high-throughput instrument to measure changes in protein expression levels in single living cells during passage in a space environment. Commercial libraries of clones expressing GFP (green fluorescent proteins) fused to individual yeast proteins are available for the entire yeast proteome. We will test the feasibility of using fluorescence measurements of these chimeric fusion proteins as an indicator of changes in the expression levels of the endogenous proteins upon exposure to radiation. Our instrument consists of a continuous, multi-well, suspension culture bioreactor that provides yeast clones that are sampled in a microfluidic flow cytometer. Light scattering and fluorescent signals from the yeast particles under flow will activate an in-line cell sorter to collect cells of interest for follow-up analysis. Since the instrument is self-contained, has low power consumption and a small footprint, and uses fluidic based cell separation, it will be suitable for collecting single cell protein expression information in a space laboratory.

Although this instrument's initial use is to study the effects of radiation on yeast protein expression, it may be applied to study effects of a space environment on any cell line grown in suspension culture, including extremeophiles. Adherent eukaryotic cells attached to microcarriers could also be used. While it purports to measure protein levels, it could also be applied to other fluorescence-based assays including mutational analysis, directed evolution studies, and screening of radioprotective compounds. Ground as well as space-based applications are contemplated. Long-term, unattended experiments are permitted by the simplicity of bioreactor design and automation of the cytometric analysis.

Many commercial applications arise for this instrument which combines a continuous cell culture bioreactor and a microfluidic flow cytometer/ cell sorter, including drug testing, combinatorial analysis, and stem cell differentiation. The bioreactor component fills an unmet need for culturing multiple clones or different cell lines under identical growth conditions in limited volumes. The cytometric analyzer/sorter provides an economical alternative to large-frame, general purpose, cell sorters in markets where high-throughput, dedicated purpose, cell screening is required. Multiple wavelength fluorescence measurements may be easily accommodated by using Geiger-mode APD arrays rather than single element APDs.