Transfer, observation and analysis of frozen hydrated specimens.

Hitherto, the observation of frozen hydrated specimens in transmission electron microscopes has been inhibited due to the technical difficulties experienced in transferring the specimen to the microscope and maintaining it at a low temperature during observation. This has resulted in loss of the primary advantage of freezing since the frozen water had to be removed from the specimen before it could be introduced into the electron microscope. The cryo-transfer system overcomes these objections and provides a means to transfer frozen hydrated specimens from any preparation equipment into the microscope without ice condensation on the specimen. The cryo-transfer system consists of a cryo-transfer unit, a cryo-specimen holder and a temperature control unit.