Optical Measurement of Transverse Molecular Diffusion in a Microchannel

摘要: Quantitative analysis of molecular diffusion is a necessity for the efficient design most microfluidic devices as well an important biophysical method in its own right. This study demonstrates rapid measurement coefficients large and small molecules device, T-sensor, by means conventional epifluorescence microscopy. Data were collected monitoring transverse flux analyte from sample stream into second flowing alongside it. As indicated low Reynolds numbers system (< 1), flow laminar, transport between streams occurs only diffusion. determinations made fitting data with predictions one-dimensional model. Analysis was development effect on distribution diffusing using three-dimensional modeling software package. Diffusion measured four fluorescently labeled molecules: fluorescein-biotin, insulin, ovalbumin, streptavidin. The resulting values differed accepted results average 2.4%. Microfluidic parameters can be selected to achieve accurate coefficient measurements optimize other that rely precise molecules.