Interferometric study on the crystal growth of tetragonal lysozyme crystal

Using a Michelson interferometer, the concentration-gradient layers around a growing hen-egg-white lysozyme, tetragonal crystal were observed. By measuring by concentration distribution and the normal growth rate, the growth mode and the diffusion coefficient of lysozyme molecules were evaluated. The experimental results indicate that the growth is regulated by two-dimensional nucleation in the supersaturation range of 6 less than or equal to sigma(surf) less than or equal to 20. The diffusion coefficient was nearly constant, 4.9 +/- 0.7 x 10(-11) m(2) s(-1) over a wide supersaturation range, differing from that of supersaturated bulk solutions.