Device for the cryo-substitution of small biological objects for microscopic research, especially electron microscopic investigations

A device for the cryosubstitution of small biological specimens for microscopic, especially electron microscopic investigations, which comprises a metal receptacle for receiving at least one specimen, a dewar flask for holding a liquid cryogen, mounting means to support said receptacle in said dewar flask above the level of the cryogen, means to regulate the temperature of said receptacle by the cryogen and a heating device, a radiation shield mounted between the underside of the receptacle and the cryogen to reduce the heat radiation from the receptacle into the into the cryogen, said receptacle being adapted to contain a substitution medium covering the specimens, whereby the specimen and substitution medium can be held at a temperature between -30.degree. C. and -120.degree. C. by a cold circulating atmosphere.