Centrifugal freezing. I. A system for rapid freezing of aqueous cell suspensions.

A centrifugal method for ultrarapid freezing of cells and subcellular particles has been developed, in which small droplets are centrifuged at high speed through liquid nitrogen. When material such as water or blood was injected from a sYI·inge into a rotor, increased rotor speeds gave progressively smaller frozen droplets. Droplet size of materials introduced from a sprayer was uniform, smaller than the smallest droplets obtained from a syringe injection, and independent of rotor speed. Cell survival was found to be inversely related to increasing droplet size and directly related to rotor speed and warming rate.-Nat Cancer lnst Monogr 21: 415-430, 1966.