CCD VIDEO OBSERVATION OF MICROGRAVITY CRYSTALLIZATION OF LYSOZYME ANDCORRELATION WITH ACCELEROMETER DATA

Lysozyme has been crystallized using the ESA Advanced Protein Crystall ization Facility onboard the NASA Space Shuttle Orbiter during the IML -2 mission. CCD video monitoring was used to follow the crystallizatio n process and evaluate the growth rate. During the mission some tetrag onal crystals were observed moving over distances of up to 200 mu m. T his was correlated with microgravity disturbances caused by firings of vernier jets on the Orbiter. Growth-rate measurement of a stationary crystal (which had nucleated on the growth reactor wall) showed spurts and lulls correlated with an onboard activity: astronaut exercise. Th e stepped growth rates may be responsible for the residual mosaic bloc k structure seen in crystal mosaicity and topography measurements.