Sparse matrix sampling: a screening method for crystallization of proteins

A set of screening conditions for initial experiments in protein crystallization has been developed, tested, and is herein presented. These solution and precipitant conditions are empirically derived based on known or published crystallization conditions of various proteins in the past, so as to sample as large a range of buffer, pH, additive and precipitant variables as possible, using small amounts of proteins. The 50 crystallization conditions have been tested on 15 previously crystallized proteins, all of which were also crystallized in at least one form by this screen. This method is also shown to be highly successful in the crystallization of proteins which had not previously been crystallized.