WorksheetsHistolab Troublehooting
Total questions: 24
Worksheet time: 12mins
Name
Class
Date
1.
What could be the cause of improper preservation of tissue?
a)
a delay in fixation
b)
rapid penetration of the fixing fluid
c)
prolonged storage in 70% alcohol following fixation
d)
an 8-hour processing cycle
2.
Tissue fixed with Bouin's should be washed in what solution following fixation to prevent picrates (yellow protein precipitates) forming?
a)
absolute alcohol
b)
50% alcohol
c)
30% alcohol
d)
saline
3.
Brown pigment appears on top of an H&E stained section. Further sections treated with iodine/sodium thiosulphate still show the pigment but those treated with alcoholic picric acid do not. How could this artifact have been prevented?
a)
washing the tissue with alcohol before processing
b)
rinsing the tissue with water before processing
c)
buffering the formaldehyde solN to pH 7.0
d)
allowing the tissue to remain in the fixative longer
4.
If tissue is left in a intolerant fixative for a prolonged time, how may it become?
a)
become excessively hard
b)
show increased autolysis
c)
show increased attraction for stains
d)
be too soft to section easily
5.
Where is the effect of acid decalcification most noticeable? Look at this over decalcified bone.
a)
collagen
b)
cytoplasm
c)
nuclei
d)
osteocytes
6.
If the clearing agent is cloudy, what is it contaminated with?
a)
absolute alcohol
b)
bacteria
c)
water
d)
wax
7.
During microtome, tissue is difficult to cut. The tissue is soft and mushy. How could your correct this from happening in the future?
a)
decreasing time in formalin
b)
increasing time in dehydrant
c)
decreasing time in dehydrate
d)
decreasing time in paraffin
8.
Sections that vary in thickness or are skipped can be caused by:
a)
block temperature being too warm
b)
nicks in the knife
c)
processing that is inadequate
d)
screws that are loose
9.
What could cause a split or lengthwise scratch in a paraffin ribbon?
a)
debris on the knife edge
b)
inadequate processing
c)
too sharp a knife edge
d)
wrong clearance angle
10.
Thyroid cut on the cryostat is chattering. What temperature is best to avoid this?
a)
-10oC
b)
-20oC
c)
-30oC
d)
-40oC
11.
When the block is being rough trimmed, the knife digs into the tissue and gouges out a chunk. What is the most likely cause?
a)
block is too cold
b)
knife is dull
c)
block is loose on the microtome
d)
cutting stroke is too rapid
12.
A paraffin block with underdecalcified bone is being sectioned. No section can be obtained. What is the best course of action to remedy this?
a)
chill the block with cryogenic spray
b)
increase the clearance angle of the knife
c)
melt the paraffin and reprocess
d)
place the faced surface on 5% HCl
13.
Mushy appearing sections may be caused by:
a)
inadequate processing
b)
overdehydration
c)
paraffin that is too warm
d)
the type of tissue processed
14.
Ragged-edge holes are seen in a tissue section of spleen when viewed with a microscope. What was this probably caused by?
a)
using vacuum on the wrong tissue
b)
excess section adhesive on the slide
c)
floaters having been picked up on the slide
d)
taking a section right after aggressive rouge cutting
15.
Microtome knives used for paraffin sectioning are usually made of:
a)
diamond
b)
glass
c)
lead
d)
stainless steel
16.
How should hard or bony tissue be embedded?
a)
on edge
b)
on an angle
c)
on edge
d)
in cross-section
17.
The temperature used to dry sections onto slides may cause deleterious effects to the tissue if the hot plate or slide drying oven is:
a)
5oC above the melting point of paraffin wax
b)
at the melting point
c)
5oC below the melting point of paraffin wax
d)
10oC below the melting point of paraffin wax
18.
During frozen sectioning, the sections slide above the anti-roll plate. This is probably due to the antiroll plate being:
a)
colder than the knife edge
b)
defective on the edge of the anti-roll plate
c)
anti-roll plate not parallel to the knife edge
d)
too far below the edge of the knife
19.
Spot the artifact
a)
fold
b)
score
c)
bubble
d)
stratification
20.
What is this artifact?
a)
ice crystal artifact
b)
chattering
c)
moth eaten effect
d)
autolysis
21.
What is this artifact caused by? Notice the sunken tissue.
a)
tissue not oriented properly
b)
poor fixation & under processing
c)
over fixation
d)
paraffin wax stratification
22.
What is the artifact caused by?
a)
Residual wax left while taking down to water
b)
Water in the last xylene
c)
tissue section place too high on slide and some parts not stained
d)
slide scratched in coplin jar
23.
Identify this artifact.
a)
bubble
b)
formalin pigment
c)
glycogen streaming
d)
stain deposit
24.
This is a section of aorta stained by Verhoeff's Van Gieson. What is the problem?
a)
poor fixation
b)
embedded wrong
c)
over differentiation
d)
poor dewaxing
100 %
