Leica Biosystems CM1950 - Manual (Page 45)

45 Leica CM1950 – Cryostat
8. Working with the Instrument
8.4 Working with the precooled cryostat
8.4.1 Preparatory work
1
2
3
To prevent injuries, remove the blade/knife holder before adjusting the
dovetail guide. Place the blade/knife holder within the cryochamber so
that it does not get warm and can be reused right after the adjustment.
• Move the specimen head forwards and out,
into the front end position.
• Move the locking lever (1) for orientation on
the specimen head (2) to the left to loosen the
specimen head.
• Now turn the setscrew (3) on the bottom of
the specimen head clockwise until you feel
the specimen head click into place.
• Move the locking lever for orientation back to
the right to lock the specimen head and make
sure that the specimen head is now stable.
• Repeat the procedure if necessary.
Fig. 54
• 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.
Fig. 52
 Specimen head adjustment:
After extended use, it is possible for the specimen head (2) to
loosen and cause artifacts when sectioning. In this case, a
simple re-adjustment is necessary.
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.
The safety gloves included in the standard scope of delivery must
be worn when working inside the cryostat chamber!
• 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.
Fig. 53