FREEZE-DRYING OF BLUE-GREEN ALGAE FOR ELECTRON MICROSCOPE STUDIES1

Cultures of Anabaena cylindrica Lemm. and Eucapsis sp. were harvested, freeze-dried, and prepared for electron microscope studies. A comparison of the freeze-dried preparations was made with control specimens not freeze-dried. Fixation and embedding were according to the Ryter and Kellenberger technique. The photosynthelic thylakoids of the freeze-dried cells were more distinct and less distorted than those of the control cells. Freeze-dried Eucapsis sp. cells exhibited a prominent mucous capsule, whereas in the nonfreeze-dried, no such capsule could be discerned.