A COMPUTER-CONTROLLED MICROSCOPY SYSTEM FOR FOLLOWING PROTEIN CRYSTAL-FACE GROWTH-RATES

A computer-controlled microscopy system for following the face growth of multiple small (approximately 10 to 50 mum) crystals during one experimental run is described. The major system components are a controlling PC with a digital oscilloscope board, PC-controlled translation stages for X, Y, and Z axes of motion, a video microscopy system, and a circuit to trigger digitization of preselected video lines. Crystal locations in the growth chamber are stored in an array, and sequentially accessed during each measurement cycle. Operator-selected horizontal video scan lines are digitized and these data are used to calculate the distance between parallel faces of the crystals. The system was assembled from readily available components, and can be easily modified for other microscopy-based tracking and measuring functions.