SHOT proposes an innovative microfluidic device designed to effect a 2-dimensional resolution of a mixture of proteins based on isoelectric point (pI) and molecular weight. A novel approach is proposed to achieve 2-D-gel equivalence. The first dimension is to be immobilized isoelectric focusing, and the second dimension will utilize an array of 100+ size-exclusion chromatography columns in microchannels. Molecular weight is recorded as each protein leaves each microcolumn. The output column number can be translated into pI. Thus each combination of output peak position and column number gives the combined values of pI and MW for each protein in the same way as does a ?spot? on a 2-D electrophoresis gel. Phase I research objectives are to (1) demonstrate the measurement of protein concentration in microchannels using a proposed electrical impedance method (2) construct and test immobiline channels and demonstrate their function in determining pI (3) construct a size-exclusion chromatography channel and demonstrate its function in determining molecular weight, and (4) identify fabrication steps for the integrated ?chip? to be tested in Phase II research. Also in Phase II research the device will be incorporated into an automatically controlled cassette configuration for operation in space flight and in the laboratory.
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