Diffusion of proteins and nonionic micelles in agarose gels by holographic interferometry

✍ Scribed by Donna D. Kong; T. Fettah Kosar; Stephanie R. Dungan; Ronald J. Phillips

• Publisher: American Institute of Chemical Engineers
• Year: 1997
• Tongue: English
• Weight: 857 KB
• Volume: 43
• Category: Article
• ISSN: 0001-1541
• DOI: 10.1002/aic.690430105

✦ Synopsis

Difision coefficients measured by holographic inteverometry are presented for two globular proteins and three nonionic suflactant species in agarose gels. The cloud points for the suflactants in agarose solutions are also given. In all cases, rates of difision in the gel are smaller than those in bulk solution, with the hindenizg effect of the gel increasing both with increasing gel concentration and with increasing solute sue. It is shown that the difision rate of the su$actant micelles is very similar to that of proteins having similar hydrodynamic radii; it would therefore appear that the size and shape of the micelles in the solution and gel phases are similar. In addition, the measured rates of hindered difSusion agree very well with rates predicted by a rigorous hydrodynamic theory in which the solutes are modeled as hard spheres and the gel fibers are modeled as straight, cylindrical fibers. Hence, for the range of conditions consdered, rates of hindered difision for both the globular proteins and the micellar species are detgrmined primarily by hard-sphere hydrodynamic and steric interactions between the solute and the gel matrix.