Quantifying main trends in lysozyme nucleation: The effect of precipitant concentration, supersaturation, and impurities

Full factorial experimental design incorporating multilinear regression analysis of the experimental data allows quick identification of main trends and effects using a limited number of experiments. In this study, we illustrate the usefulness of these techniques in macromolecule crystallization studies, by employing them to identify the effect of precipitant concentration, supersaturation, and the presence of an impurity, the physiological lysozyme dimer, on the nucleation and dimensions of chicken egg white lysozyme crystals. Decreasing precipitant concentration, increasing supersaturation, and increasing impurity were found to increase crystal numbers. The crystal axial ratio decreased with increasing precipitant concentration, independent of impurity.