How does temperature affect crystal formation?

Temperature also affects crystal growth because the higher the temperature, the hotter the crystalline solution is and the faster its molecules move. This movement allows them to evaporate more quickly, leaving particles that turn into crystals. Crystals grow faster in warmer temperatures because the liquid containing the dissolved material evaporates quickly. Therefore, the improvement in crystal quality that was observed could be due to the fact that the pre-cooling of the various components (tips, solutions and trays) of the crystallization configuration led to a lower level of supersaturation in the droplets.

The probability of nucleation and crystal growth is greater the further the system is pushed into the region of supersaturation. The first crystallization experiment was performed with the crystallization plate in the bank at a temperature of 294 to 296 K and with deposit solutions at approximately 294 to 296 K. This could result in better quality crystallization cores and, due to a lower growth rate, fewer imperfections within the crystals. Spontaneous protein precipitation was reduced and the crystal shape could be improved by lowering the temperature during the crystallization configuration.

The second experiment was performed with the crystallization plate in the bank at 294-296 K and the tank solutions that had been previously cooled overnight in a refrigerator (∼277 K) and kept on ice during the crystallization setup. Crystallization was carried out manually by diffusion of vapor into droplets hanging in 24-well crystallization plates (Greiner Bio-One, item No. To investigate the influence of temperature, crystallization plates with identical crystallization conditions are often stored at different temperatures. We observed that placing the crystallization plate on ice, cooling the tank solution (to approximately 277 K) and using pre-cooled pipette tips had a positive effect on the crystal shape and reduced the formation of precipitates.

For several typical crystals from each crystallization experiment, diffraction images were recorded to test resolution. In these experiments, crystal growth stopped again after 2 days and the crystals remained stable for several weeks to months. For the crystals obtained in the first, second and third crystallization experiments, the 95th percentile resolution of all the reflections in the best image was 3.83, 3.64 and 3.27 A, respectively.