Cryostat having separate cooling circuits for cooling the chamber and a sample holder

Abstract: According to an aspect of the present invention, a cryostat includes two separate cooling means, one for reducing the temperature in a cooling chamber (2) and the other arranged to cool a freezing plate (8). In one embodiment, there may be a single cooling circuit, with e.g. a single reservoir of refrigerant, but with a separate compressor provided for each of the cooling means i.e. one compressor to control the temperature within the cooling chamber (2) and a separate compressor for the cooling circuit associated with the freezing plate (8). In accordance with another aspect of the present invention, the freezing plate (8) includes means for retaining some liquid on the surface of the freezing plate. In an embodiment, these means are provided by a lip (12). In a further aspect a friction generating means provides resistance to the movement of the microtome head, for example by providing a spring loaded collar on rotatable shaft. In a further aspect a cryostat is provided with a touch screen display.