title: Freezing and Viability of Tetrahymena pyriformis in Dimethylsulfoxide.
abstract: Ciliated protozoa may be preserved at very low temperatures. Tetrahymena pyriformis, suspended in 10 percent dimethylsulfoxide, survived when frozen in two steps, first to -20 degrees C, then transferring immediately to a temperature of -196 degrees C. Motility and ability to reproduce were recovered after freezing by this method and subsequent storage for 3 months in a liquid nitrogen refrigerator.
authors.forename: S W
authors.initials: SW
authors.lastname: Hwang
authors.forename: E E
authors.initials: EE
authors.lastname: Davis
authors.forename: M T
authors.initials: MT
authors.lastname: Alexander