Convection-free environments for protein crystallization: a competition between physical and chemical interactions

The elimination of convection from crystallization environments is often desirable as it hinders crystal sedimentation, reduces the risk of crystal breakage, and allows for more controlled crystallization conditions. In this scenario, gels can be used to establish purely diffusive conditions for the nucleation and growth of protein crystals. Depending on the precursor molecules, gels possess inducing or inhibiting ability towards the crystallization of proteins. This ability is a consequence of both the introduction of a new interface within the crystallization environment and the modification of its physical properties, i.e., porosity, elasticity, viscosity, etc. In the present work, the effect of agarose and silica-based gels on protein crystallization is investigated.