Leica Biosystems CM1950 - Manual (Page 51)

Leica CM1950 – Cryostat 51
9. Troubleshooting
9.1 Problems during work
Problem Cause Remedy
Frost on chamber walls and
microtome
Cryostat is exposed to air currents
(open windows and doors, air
conditioning).
Frost built-up by breathing into the
cryochamber.
Move to a draft-free location.
Wear mouth protection.
Sections smear Specimen not cold enough.
Anti-roll plate not yet cold enough,
thus warming the section.
Select lower temperature.
Wait until knife and/or anti-roll
plate have reached chamber
temperature.
Sections splinter Specimen too cold. Select higher temperature.
Sections not properly
flattened
Static electricity/air currents.
Specimen not cold enough.
Large area specimen.
Anti-roll plate poorly positioned.
Anti-roll plate poorly aligned with knife
edge.
Incorrect clearance angle.
Blunt knife.
Remove cause.
Select lower temperature.
Trim the specimen parallel, increase
section thickness.
Reposition anti-roll plate.
Align correctly.
Set correct angle.
Use different part of the knife.
Sections not properly
flattened despite correct
temperature and correctly
aligned anti-roll plate
Dirt on knife and/or anti-roll plate.
Edge of anti-roll plate damaged.
Blunt knife.
Clean with dry cloth or brush.
Replace anti-roll plate.
Use different part of the knife.
Sections curl on anti-roll
plate
Anti-roll plate does not protrude far
enough beyond the knife edge.
Readjust correctly.
Scraping noise during
sectioning and specimen
return movement
Anti-roll plate protrudes too far
beyond the knife edge and is scraping
against the specimen.
Readjust correctly.