Despite intensive research, the crystallization of biological macromolecules remains a process of trial and error. Nucleation and crystal growth are influenced by the interaction of many variables, such as temperature, pH, precipitant and salt concentration.
Testing all possible combinations would be too time consuming and would require enormous amounts of sample. One approach to find suitable crystallization conditions is the sparse-matrix method. This method involves screening with an intentional bias towards conditions which have been proven successful in the crystallization of biological macromolecules.
In 1991, Jancarik and Kim published 50 conditions, which were derived from previously crystallized proteins [1]. These and other conditions form the basis of the JBScreen Basic system [1,2]. However, JBScreen Basic is designed to fit the 24-well plate format and like in all other JBScreen crystallization kits, we abstained from the use of cacodylate buffers and replaced them with MES. JBScreen Basic contains 96 unique reagent mixtures for screening a wide range of pH and various salts and precipitants.
Bulk – 24 or 96 screening solutions in 10 ml aliquots
HTS – 96 screening solutions delivered in a deep-well block, 1.7 ml per well
[1] Jancarik and Kim (1991) Sparse matrix sampling: a screening method for crystallization of proteins. J. Appl. Cryst. 24:409.
[2] Cudney et al. (1994) Screening and optimization strategies for macromolecular crystal growth. Acta Cryst. D 50:414.