Observation of the concentration distribution around a growing lysozyme crystal

Abstract

The optical path length distribution of the solution around a growing lysozyme crystal was observed in situ using a Michelson interferometer of the reflection type. From the interferograms, a concentration profile around a growing crystal and the growth rate were obtained and thus, we could evaluate the diffusion coefficient of the lysozyme molecules to be 1.59 × 10 -10 m 2/s. The measurement of the viscosity of the solution rendered it possible to estimate the Stokes radius of the diffusing entities which coincided with the crystallographic size of a lysozyme molecule.