POLYTHERMAL SCREENING AND PRODUCTION METHODS FOR MACROMOLECULAR CRYSTALLIZATION. George T. DeTitta, Dawn M. Dembik, Walter A. Pangborn and Joseph R. Luft. Hauptman-Woodward Medical Research Institute, 73 High Street, Buffalo, NY 14203.

Macromolecular crystal growth can be logically divided into a screening stage and a production stage. In the screening stage many or all of the parameters known to affect the outcome of a crystal growth experiment are sampled in order to identify promising candidate sets of parameters for future optimization. In the production stage the candidate sets are optimized to produce crystals of adequate size and quality for diffraction work. We are currently developing three devices based on the thermal gradient. One of these devices is optimized for the screening stage. It allows the simultaneous sampling of many conditions and requires a minimum of sample. Another is optimized for the production stage. It allows for the growth of large crystals and therefore requires larger macromolecular samples. The third device is a hybrid; it allows for both screening and production when samples are plentiful. All three employ gradients operated between 283K and 313K. Results from crystallization experiments conducted with the three devices will be discussed.

This work was supported in part by NIH Grant GM51670 and NASA Grant NAG8-1152.