Cryomicroscopy of isolated plant protoplasts

It has been nearly 100 years since Müller-Thurgau (26) employed cryomicroscopy to identify the cooling rate dependency of intracellular ice formation. Since that time cryomicroscopy has advanced from the “ice age” when Molisch (23) packed his microscope in ice to the “space age” of today when computer hardware developed for space satellite imagery is used for cryomicroscopic image analysis. Although interest in cryomicroscopy has been sporadic in the intervening period, current interest is at a high level—largely as a result of the refinement in the cryomicroscope design by Diller and Cravalho (9). The increased sophistication in cryostage design and precision of temperature control allow for quantitative studies of cell behavior during a freeze-thaw cycle. Not only does quantitative video image analysis facilitate this task, but it provides for increased resolution of cellular and subcellular responses during the freeze-thaw cycle. Most importantly, cryomicroscopy presents a researcher with a panorama of cellular behavior within which existing facts can be placed in perspective and from which future experiments can be more accurately focused.