Magnetically controlled gravity for protein crystal growth
M. C. R. Heijna, P. W. G. Poodt, K. Tsukamoto, W. J. de Grip, P. C. M. Christianen, J. C. Maan, J. L. A. Hendrix, W. J. P. van Enckevort and E. Vlieg

Abstract:
The occurrence of convective flows during crystal growth is believed to adversely affect crystal quality. Space-based crystal growth is therefore actively pursued, particularly for protein crystals, because buoyancy-driven convection is suppressed in microgravity. Here the authors demonstrate that magnetic fields can be used to tune the effective gravity from 1  to  −0.15  g during the growth of diamagnetic lysozyme crystals and that convection can be damped, stopped, and even reversed. The growth velocity is strongly reduced in simulated microgravity. This method provides a versatile and accessible way to realize an earth-based tunable gravity environment for crystal growth in which protein crystal quality may be optimized.