The freezing rate of freeze-etch specimens for electron microscopy

Experiments on the rapid freezing of freeze-etch sized specimens have shown this rate between 0 and ?100 °C to be approximately 1000 °C/sec. This is much faster than the rate of 100 °C/sec estimated by Moor for specimens cooled in liquid Freon 12.Heat transfer from the rapidly immersed specimen and mount appears to be mainly through forced convection. Such a mechanism would make the initial rate highly variable as it would be sensitive to liquid velocity. If this occurs it will be impossible to obtain consistent results for freezingrate studies unless a stable method is evolved for both injecting and containing the specimen.