8.Working with the Instrument
8.4Working with the Precooled Cryostat 8.4.1 Preparatory Work
•Lock the handwheel in the top (12 o’clock) position.
•Cut the specimen to size outside of the cryostat.
•Select the precooled specimen disc, cover it with freezing compound, then attach and orient the specimen.
•Attach the specimen disc and specimen to the Peltier position on the freeze shelf. Activate the Peltier element and wait until the specimen is completely frozen.
Specimens that have been frozen on the Peltier element are often too cold and split apart during sectioning. Allow time for the speci- mens to become acclimated.
•Insert the specimen disc into the specimen head.
•Fold the
Before using them for the first time, degrease new knives using acetone or alcohol.
•Approach the specimen with the knife or blade holder:
•To do so, open the clamping lever of the base, approach the specimen and close the lever again.
•Open the lever of the orientation. Orient the specimen (move it into a favorable position relative to the knife/blade) and close the lever again.
•Approach the knife or blade holder using the coarse feed buttons and gentle movements of the handwheel.
If the sections are cracked, the specimen head temperature is too cold. Set a warmer temperature.
If the sections smear, the specimen head temperature is too warm.
Set a colder temperature.
42 | Operating Manual V1.1 – 05/2007 |