914 Nitrogen Cooled Cryotransfer Tomography Holder

Applications

TEM cryotransfer holders are primarily used to reduce specimen damage caused by the electron beam and to observe biological macro-molecules in the hydrated state. Sensitive biological and polymer specimens are rapidly frozen, loaded into the cryotransfer holder in a special liquid nitrogen cooled workstation and transferred to the microscope goniometer. Specimens are protected from frost and warming during transfer by a shutter, which totally encloses the specimen.

Low drift and high resolution

Gatan Cryotransfer holders achieve their high mechanical stability by conduction cooling from well insulated, bubble-free dewars. The holder rod is designed to minimize cold leaks into the goniometer and hence minimize drift.

Precise temperature control

The specimen holder tip temperature is measured as close to the end tip as possible in order to give the most accurate reading of specimen temperature. Intermediate temperatures may be selected using the rod-mounted heater.

Rapid, frost-free transfer

Gatan technology made frost-free transfer possible with the introduction of the Cryoshield in 1980, and we have continued to provide new concepts to preserve specimen integrity. In the model 914 a cryo-shield slides over the specimen boat completely enclosing the specimen. This shutter is cooled by the conduction rod and actuated by a sliding knob mounted on the back of the nitrogen dewar.

Optimized specimen loading

The cryo-workstation incorporates many features to facilitate and optimise the loading of frozen specimens. The ‘Quickload’ loading system is mounted in the workstation tray and allows easy and quick positioning of the specimen in the holder. No screws need to be loosened and the specimen is automatically centred when inserting. Forceps and ‘Quickload’ tool can be pre-cooled in the workstation and a specimen storage box is
provided for up to 4 specimens.

Secure specimen clamping system

Grids or specimens are held firmly but gently by the clamping springs, which are flexible enough to take up variations in specimen thickness.

Holder in cryo-workstation showing ‘Quickload’ support and release mechanism