Improved methods for controlled rapid cooling of cell suspensions.

Simple, reproducible, methods of achieving rapid rates of cooling in the range 100 degrees C min(-1) to 1000 degrees C min(-1) are described for straws and cryovial. These methods use the direct contact of straws or cryovials with pre-cooled granules or plates as the heat sink. Liquid nitrogen may be adsorbed into suitable material, for example activated charcoal, zeolites and molecular sieves as the matrix to achieve rapid cooling. Controllable rapid rates of cooling may also be attained by using non-adsorbants. The rate of cooling may be modified by changing the adsorbant material, the size of the adsorbant granules and the temperature of the adsorbant.