Bright Instruments
34
2.3 MICROTOME CONTROLS SOLID
KNIFE
Refer to Figure 2.
2.3.1 KNIFE GUARD
The knife guard is fitted to the knife block
with a retaining wire to ensure it cannot be
misplaced. When a knife is installed, the guard
should be in position over the knife only being
removed when access is required.
2.3.2 KNIFE HOLDER
To ensure optimum sectioning performance
the knife must be kept clean from grease and
dirt. To clean the knife, carefully apply a small
amount of methylated spirits or ethanol to
the surface of the knife using a clean, dry, soft
paper towel. Always move the towel away
from the edge of the knife - never towards it.
To install a knife, loosen the knife clamp
screws and slide the knife in from the left.
Before re-tightening the knife clamp screws,
set the knife tilt angle scale and lock into
position. The correct setting of the knife angle
is essential for obtaining good results see
table below.
To remove a knife, loosen the knife clamp
screws, remove the knife guard and slide the
knife out through to the left.
See the table below for a list of recommended
knife angles.
Part No.
Description
Angle (+/- 2.5)
50230
Standard knife
15º
50232-1
Hardened steel
knife
12º
50207
Steel knife
15º
50234
Tungsten carbide
tipped knife
25º
2.3.3 ANTI-ROLL ASSEMBLY
Refer to Figure 3.
The Anti-Roll plate is a device for ensuring
that tissue sections pass down the blade face
without curling, so that they can be collected
flat on to microscope slides.
The setting up of the Anti-Roll plate is second
only in importance to the quality of the blade
edge in obtaining ribbons of high quality
sections.
Step 1: Preparation
a. Install a sharp Bright microtome knife,
setting the appropriate clearance angle for
that particular knife.
b. Clamp a frozen specimen (or embedding
compound alone) into the microtome (refer to
section 3.2)
c. Release the knife block clamp locking
lever and turn the knife carriage feed control
clockwise to bring the knife towards the
specimen.
d. Trim the specimen or embedding medium
until a suitable block face is made (refer to
section 3.3).
e. Lock the knife carriage clamp firmly
and proceed to cut sections at the chosen
thickness. Once it can be seen that regular,
good quality sections are cut (albeit curled
up) go on to step 2.
2. Operation Instructions
Cont.
