Novel and Simple Screening Methods for Protein Crystallization by Vapor Diffusion Rate Control

We investigated the effect of the vapor diffusion rate on the refinement of protein crystals. The reservoir volume, drop-to-reservoir distance, and air space were altered to change the vapor diffusion rate using a very dense insoluble liquid and specific crystallization plates. The experimental results reveal that the drop-to-reservoir distance and air space have a more significant effect on crystal growth than the reservoir volume. We propose new simple and useful methods for screening protein crystal growth conditions based on vapor diffusion rate control.