A manual nanoscale method for protein crystallization.

To overcome one of the major hurdles in three-dimensional crystal structure determination - the requirement for large quantities of purified material to grow crystals - crystallization methodologies have been developed that require only a total of 2-5 microl of a concentrated macromolecular solution to screen more than 100 conditions. These procedures employ a circular slide containing an array of 25 wells designed for crystallization setups in the nanolitre volume range. These 'crystallization slides' fit into the wells of standard crystallization trays. These nanoscale crystallization approaches have been used to reproducibly obtain well diffracting crystals of three proteins, two that are being actively studied (glycerol kinase and NADH peroxidase) and one test protein (lysozyme), using only 40-350 microg (0.04-0.35 mg) of proteins to screen 100 conditions. These nanolitre crystallization methods are easily adapted for the typical laboratory, without the requirement of robotics or expensive equipment.