Leica Biosystems CM1520 - Manual (Page 37)

37 Leica CM1520 – Cryostat
7. Daily Use of the Instrument
Clearance angle adjustment
Adjust the clearance angle with every new tis-
sue type!
1. The clearance angle scale is located on the
left side of the blade holder.
2. Release the blade holder by turning the No. 4
Allen screw (23) counterclockwise. Select
a clearance angle of 0°. To do so, align the
number 0 to the index mark (25) and tighten the
Allen screw (23). If the sectioning results are
not satisfactory, increase the clearance angle
in 1° increments until you achieve optimum
results.
25
Fig. 35
23
• A clearance angle that is too steep or too shallow may not lead to optimum sectioning results
and can possibly damage the specimen. We generally recommend using higher clearance
angles for harder specimens and relatively lower clearance angles for softer ones.
Settings of 1° - 2° (blade holder CE) are
well suited for most applications.
The harder the specimen is, the larger the clearance angle must be.
However: The larger the clearance angle is, the larger the section buckling becomes.
If the clearance angle is too small, sections that are too thick or thin can result. Also
consider that the position of the knife edge relative to the specimen can change when
the clearance angle is adjusted. For this reason, always place the specimen above the
knife when adjusting the clearance angle. Otherwise, the specimen could hit the knife
while being raised.