[LAB] Trimming Flashcards
It is the removal of excess wax from the paraffin block to expose the tissue surface in preparation for actual cutting.
Trimming
The process of cutting the specimen prior to embedding is also called as Trimming
False
It is sometimes referred to as ‘facing’ or ‘rough cutting’
Trimming
The most desirable block does not exceed . mm
0.5 mm
Fill in the blank:
The sides, top, and bottom of the tissue block are trimmed until perfectly level and all sides are ______, almost to the edge of the tissue.
Parallel
T/F
Before we get to the embedded tissue, the paraffin between the sample and surface of the block needs to be removed by trimming, first by hand and latter with the microtome by making sections until the first section with tissue appears.
True
(T/F)
You can use an old dull knife or blade for trimming
False.
You can use an old knife or blade but it needs to be SHARP.
Why do we need a shrap knife for trimming?
To avoid damage to the tissue
We must sculpt the paraffin block in order to make a ________ ___________ with a ________ _________ _______
truncated pyramid with a trapezoidal upper surface
We must “_____” the paraffin block in order to make a truncated pyramid with a trapezoidal upper surface
“sculpt”
(T/F)
Trimming should be trapezoidal because:
the longest edge of the upper surface is the first to be cut, whereas the smaller edge will be the last.
True!
Both edges need to be ________. In this way, the large edge for a new section displaces the previous section, which is attached to the blade by the shorter edge.
parallel
(T/F)
Because both edges are parallel, short and straight rows of sections can be obtained in this way.
False.
**LONG **AND STRAIGHT
GENERAL TIPS IN TRIMMING
(T/F)
Paraffin blocks are cooled prior to trimming
True
GENERAL TIPS IN TRIMMING
Trim away excess wax carefully to expose a suitable
area of the _______.
Tissue
Where do you fix the block into and secure it?
Chuck holder
GENERAL TIPS IN TRIMMING
(T/F)
Fine trim the block face in preparation for sectioning. An old blade may be used for this purpose.
False.
New blade
Depending upon the ____ and _____ of the tissue sample, shave conservatively into the block surface taking appropriate cuts that may measure between 4-60 micrometers.
Size and Orientation
Samples of _______ biopsy tissue may be trimmed only to the depth of the first representation of several levels that will be collected.
small
When using the coarse feed, avoid cutting _________ thick sections as this will damage the knife and possibly the block face.
unintentional
Aggressive trimming will cause “______ ______ ” artifacts.
Moth hole
COARSE TRIMMING
Coarse facing is done on the microtome at approximately __ - __ microns at a time until the entire tissue surface is exposed.
15-30 microns
Do you ensure that the block clamped in the chuck has been retracted so that there is no contact with the blade on the initial downstroke?
Yes
It is possible to damage the tissue by _____ or _____ when trimming the block
Gouging or scoring
