Cryogenic sample preparation is an alternative to chemical fixation of biological tissue.
Samples are rapidly frozen, thereby preserving the structural, elemental and immunological properties of the sample. This does not give water molecules time to organise into crystals, which results in vitreous or non-crystalline ice. The structure of the sample, including the location of elements and proteins, are immobilised down to the atomic level.
Leica EMPACT2 high-pressure freezer
A state-of-the-art instrument that is able to rapidly freeze tissues, cell cultures or fluids to a depth of approximately 200 micrometers in the vitreous state.
Leica EM AFS2 automatic freeze-substitution unit
The AFS is used for warming cryogenically frozen samples back to room temperature prior to further processing. Various protocols are used depending on the tissue (plant/animal) and the types of analyses required (structural/elemental/immunological).
Emitech K775X turbo freeze-dryer
Specifically designed for drying samples frozen in liquid nitrogen, the K775X freeze-drier is an alternative to SEM preparation techniques such as critical point drying. Water is sublimed from small samples by slowly warming them under vacuum.
Leica EM UC6 cryo-ultramicrotome
This microtome is used for creating thin sections of biological materials. It can be operated at either room temperature, for standard resin embedded tissue, or at liquid nitrogen temperatures for sectioning vitreously frozen samples.
Leica VCT100 and MED020 cryoSEM preparation
The VCT100 in combination with the MED020 system is used to prepare and image frozen samples in the SEM. The system allows samples to be fractured, sublimated, microplaned and metal-coated at low temperatures, prior to imaging and/or analysis at low temperatures in the Zeiss FESM.
Oxford Plunge freezer
Used to rapidly freeze specimens in liquid nitrogen slush, prior to further processing (substitution, drying, SEM).