title: Protein diffusion coefficient measurements by laminar flow analysis: method and applications.
abstract: Laminar flow in an open tube leads to solute band spreading. This process is opposed by radial diffusion. The translational diffusion coefficient of a solute can be calculated from the band dispersion, tube length, and flow rate. No calibration is necessary. A simple apparatus was used to measure the diffusion coefficients of several small solutes and 18 proteins. Most results were within +/- 10% of literature values. Each determination required 7-90 min, depending on the magnitude of the diffusion coefficient. The amount of protein needed was approximately 25 micrograms. The diffusion coefficient data were useful for the estimation of molecular weights.
mesh_terms: D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002845:Chromatography / Q000295:instrumentation; D004058:Diffusion; D008433:Mathematics; D008956:Models, Chemical; D008970:Molecular Weight; D011506:Proteins / Q000032:analysis*
chemical_list: D011506:Proteins