Spray-freezing apparatus for cryofixation of unicellular algae

• DOI: 10.1017/s0424820100146515
• Publication Date: 2020-06-18T09:53:16Z
• Authors: Stephen D. Fields; Gregory W. Strout; Scott D. Russell
• Keywords: 0301 basic medicine; 03 medical and health sciences; 6. Clean water

Spray freezing unicellular organisms directly from the culture medium is an attractive alternative to other methods of rapid freezing because the possibility of pre-freezing artifacts is minimized. However, the utility of spray-freezing has been limited due to difficulties in obtaining satisfactory freezing in large specimens and in collecting and processing specimens after freezing. Consequently, the design of many spray-freezing devices is somewhat complicated, of limited application and often difficult to use. A simple, inexpensive spray-freezing apparatus of our own design was developed with the purpose of rapid freezing unicellular algal suspensions for freeze substitution. A naked, freshwater dinoflagellate was used to determine the effectiveness of the freezing device and the associated freeze substitution protocol.