An electromechanical apparatus fdr rapid tissue freezing]

1006. 1967.-An apparatus for rapid freezing of rat heart and other tissue specimens is described. A heart whih was excised from a rat was compressed to a flat disc and simul-taneously frozen in an aluminum freezing apparatus which had been precooled in liquid nitrogen. liquid nitrogen; rat heart and olaced flat on the laboratory bench. The heart is ouicklv 1 excised from the animal, dropped into the apparatus, ahd thk tissue compressed and frozen by depressing the foot switch. Heat absorption by the apparatus from the environment was determined by removing it from liquid nitrogen, exposing it to room temperature (22 C) for specific time intervals (O-300 set), and then plunging it into alcohol kept in a heat-insulated beaker. The decrease in temperature of the alcohol was ob