Automated high-throughput nanoliter-scale protein crystallization screening

A highly efficient method is developed for automated high-throughput screening of nanoliter-scale protein crystallization. The system integrates liquid dispensing, crystallization and detection. The automated liquid dispensing system handles nanoliters of protein and various combinations of precipitants in parallel to access diverse regions of the phase diagram. A new detection scheme, native fluorescence, with complementary visible-light detection is employed for monitoring the progress of crystallization. This detection mode can distinguish protein crystals from inorganic crystals in a nondestructive manner. A gas-permeable membrane covering the microwells simplifies evaporation rate control and probes extended conditions in the phase diagram. The system was successfully demonstrated for the screening of lysozyme crystallization under 81 different conditions.