PROTEIN CRYSTAL-GROWTH RATES DETERMINED BY TIME-LAPSE MICROPHOTOGRAPHY

Time lapse video microscopy has been used to make qualitative observations of the events that transpire during normal and abnormal protein crystal growth. It has also been used to make quantitative assessments of growth rates for a variety of different protein crystals. From analyses of the growth rates, we have estimated that in the most rapidly growing crystals we have recorded, as many as 20 layers of protein molecules add to a single crystal face per second. In the slowest cases of growth, such as virus crystals, a minute or more may be required for addition of a single layer. In almost all cases, growth was linear over nearly the entire period of growth before leveling near growth termination. We present here a small but typical sample of the results obtained using the time lapse video microscopy technique.