A comparison of microbatch and vapour diffusion for initial screening of crystallization conditions

Six commercially available proteins were screened using the ''sparse matrix'' solutions of Jancarik and Kim (with modifications by Hampton Research Inc.). The screens were performed using the most common vapour diffusion method and three variants of the microbatch crystallization method, including a novel evaporation technique, Out of 58 crystallization conditions identified, 43 (74%) were identified by microbatch, while 41 (71%) were identified by vapour diffusion. 26 conditions were found by both methods, and 17 (29%) would have been missed if microbatch had not been used at all. The evaporation technique provided the best microbatch method finding a total of 34 conditions.