At the end of a day in a Kerala histopathology laboratory, these items must be segregated under the Bio-Medical Waste Management Rules 2016: used microtome blades, broken glass slides, formalin-fixed tissue trimmings and used nitrile gloves. Which segregation is correct?

Blades white, slides blue, tissue yellow, gloves red

Blades blue, slides white, tissue yellow, gloves red

Blades yellow, slides blue, tissue yellow, gloves black

Blades white, slides blue, tissue red, gloves yellow

In the Kaiserling method of museum specimen preparation, the fixed specimen is moved into 80 to 95% ethanol (Kaiserling II). This step:

Restores the natural colour of the tissue

Fixes the tissue without shrinkage

Hardens fat so it can be cut cleanly

Removes the smell of formalin for good

For quality control of a special stain, which is the best positive control section?

Tissue with a small, known amount of target

A second section from the patient's block

Frozen tissue kept specially for controls

Tissue with a very large amount of target

Sodium dithionite (sodium hydrosulphite) is added to some museum mounting fluids. What is its purpose?

Keep the restored red colour as a reducing agent

Raise the refractive index of the fluid

Prevent fungal and bacterial growth inside the sealed jar

Complete fixation of the deeper tissue

During a stock check, a technologist finds an old bottle of picric acid at the back of a cupboard. The contents look dry, and yellow crystals are crusted around the screw cap. What should be done?

Leave it closed and call hazardous-waste disposal

Open it in a fume hood and dissolve the crystals

Unscrew the cap and add water to re-wet it

Wash the crystals down the sink with plenty of water

Museum technique, quality and safety in histopathology

13 Kerala MSc MLT Entrance practice questions on Museum technique, quality and safety in histopathology, part of Pathology. The first 13 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

Question 1 · Hard
At the end of a day in a Kerala histopathology laboratory, these items must be segregated under the Bio-Medical Waste Management Rules 2016: used microtome blades, broken glass slides, formalin-fixed tissue trimmings and used nitrile gloves. Which segregation is correct?
1. ABlades blue, slides white, tissue yellow, gloves red
2. BBlades white, slides blue, tissue yellow, gloves red
3. CBlades yellow, slides blue, tissue yellow, gloves black
4. DBlades white, slides blue, tissue red, gloves yellow
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Answer: B · Blades white, slides blue, tissue yellow, gloves red
Metal sharps such as blades and needles go in the white, translucent, puncture-proof container. Contaminated or broken glass, including slides, goes in the blue-marked cardboard box or container. Human anatomical waste, including tissue, goes in the yellow bag for incineration. Contaminated recyclable items such as gloves and tubing go in the red bag for autoclaving and recycling.
- A: Blades are metal sharps (white) and glass slides belong in blue, not the reverse.
- C: Blades go in white, and black is not a biomedical waste colour in these Rules.
- D: Tissue is anatomical waste for the yellow bag, and gloves go in red.
Question 2 · Easy
In the Kaiserling method of museum specimen preparation, the fixed specimen is moved into 80 to 95% ethanol (Kaiserling II). This step:
1. ARestores the natural colour of the tissue
2. BFixes the tissue without shrinkage
3. CHardens fat so it can be cut cleanly
4. DRemoves the smell of formalin for good
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Answer: A · Restores the natural colour of the tissue
In Kaiserling I the specimen is fixed in formalin containing potassium acetate and potassium nitrate, which helps preserve the colour of blood pigment. After washing, it is placed in ethanol (Kaiserling II) until the natural red colour returns, usually within an hour, and it is watched because too long in alcohol fades the colour again. It is then mounted in Kaiserling III, a fluid of glycerine and potassium acetate in water. The jar is sealed to keep air out.
- B: Fixation is done in the formalin-based Kaiserling I solution.
- C: Ethanol is used only briefly here and is not meant to harden fat.
- D: Washing and the mounting fluid deal with formalin; this step is for colour.
Question 3 · Medium
For quality control of a special stain, which is the best positive control section?
1. ATissue with a small, known amount of target
2. BA second section from the patient's block
3. CFrozen tissue kept specially for controls
4. DTissue with a very large amount of target
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Answer: A · Tissue with a small, known amount of target
A control with only a small or moderate amount of target shows a slight loss of sensitivity, which a heavily positive control can hide. It should be fixed and processed like patient tissue, normally in formalin and paraffin, so it reacts in the same way. Placing it on the same slide as the patient section ensures both see exactly the same reagents and timing. Control results are recorded for every run, as NABL and ISO 15189 require.
- B: The patient's own block cannot prove that the method worked.
- C: Frozen tissue is not processed like the paraffin sections it should check.
- D: A strongly positive control may still stain when the method is failing.
Question 4 · Medium
Sodium dithionite (sodium hydrosulphite) is added to some museum mounting fluids. What is its purpose?
1. AKeep the restored red colour as a reducing agent
2. BRaise the refractive index of the fluid
3. CPrevent fungal and bacterial growth inside the sealed jar
4. DComplete fixation of the deeper tissue
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Answer: A · Keep the restored red colour as a reducing agent
Air entering the jar slowly oxidises blood pigments, and the specimen turns brown. Sodium dithionite is a reducing agent that maintains, and can partly restore, the natural colour of the haemoglobin pigments. Because it is used up by oxygen, the jar must be sealed airtight, and the fluid is changed if the colour fades. Glycerine in the fluid sets the refractive index and helps prevent drying.
- B: Glycerine, not dithionite, adjusts the refractive index of the fluid.
- C: Mould is prevented by preservatives such as thymol or formalin, not by dithionite.
- D: The specimen is already fully fixed before it is mounted.
Question 5 · Hard
During a stock check, a technologist finds an old bottle of picric acid at the back of a cupboard. The contents look dry, and yellow crystals are crusted around the screw cap. What should be done?
1. ALeave it closed and call hazardous-waste disposal
2. BOpen it in a fume hood and dissolve the crystals
3. CUnscrew the cap and add water to re-wet it
4. DWash the crystals down the sink with plenty of water
Show answerHide answer
Answer: A · Leave it closed and call hazardous-waste disposal
Dry picric acid (trinitrophenol) is a shock- and friction-sensitive explosive, and crystals in the cap threads can detonate when the cap is turned. The bottle must not be opened or moved roughly; the area is cleared and trained hazardous-waste staff are called. Picric acid is stored wet, under a layer of water, and checked regularly. It also forms highly sensitive picrates with metals such as copper and lead, so it must never go down metal drains.
- B: A fume hood does not protect against an explosion when the cap is opened.
- C: Turning the cap can detonate friction-sensitive crystals in the threads.
- D: Picric acid forms explosive picrates with metal pipes and must not go down the drain.
Question 6 · Easy
A lung removed at autopsy is to be preserved as a museum specimen. What is the best way to fix it?
1. AInflate it with fixative through the main bronchus
2. BInject fixative through the pleural surface
3. CFreeze it first and then thaw it in formalin
4. DImmerse it, still collapsed, in a large jar of formalin
Answer and explanation in LearnFree account
Question 7 · Medium
What is the Gough-Wentworth technique used to prepare?
1. APlastic-embedded slices of whole bone
2. BFrozen sections of whole brain
3. CColoured casts of the renal pelvis
4. DThin whole-lung slices mounted on paper
Answer and explanation in LearnFree account
Question 8 · Medium
A whole brain removed at autopsy is to be fixed for the museum without flattening its shape. The usual way is to:
1. ALay it on the floor of a jar of 10% formalin
2. BPerfuse it through the bronchi with formalin
3. CSlice it into coronal sections before any fixation
4. DSuspend it by a thread under the basilar artery in formalin
Answer and explanation in LearnFree account
Question 9 · Easy
In the Kaiserling method, the final mounting fluid (Kaiserling III) keeps the specimen moist and clear mainly because it contains:
1. AGlycerine
2. BXylene
3. CPotassium nitrate
4. DEthanol
Answer and explanation in LearnFree account
Question 10 · Hard
A Perls' Prussian blue run uses a liver section with known haemosiderosis as control. The control shows no blue granules, and a bone marrow clot section from a patient with suspected iron overload is also negative. What is the correct action?
1. ARepeat the run with fresh reagents and withhold the report
2. BReport the result and add a comment about the control
3. CRepeat only the patient section and keep the same reagents
4. DReport the patient section as showing no stainable iron
Answer and explanation in LearnFree account
Question 11 · Medium
A technologist needs to take a block out of the chuck of a rotary microtome. What should be done first?
1. AWipe the knife edge clean with gauze from back to front
2. BLock the handwheel and cover the knife edge with the guard
3. CMove the block to its highest point and reach in carefully
4. DRemove the blade first and then release the block clamp
Answer and explanation in LearnFree account
Question 12 · Hard
A 900 mL spleen is to be fixed for the museum in 10% formalin, using a fixative volume 10 times that of the specimen. Stock formalin is 40% formaldehyde. How much stock formalin is needed?
1. A9,000 mL
2. B900 mL
3. C450 mL
4. D2,250 mL
Answer and explanation in LearnFree account
Question 13 · Medium
On a section from a cervical biopsy, a small fragment of colonic mucosa lies at the edge of the slide, separate from the biopsy and outside its plane of section. The most likely source is:
1. AWrong labelling of the patient's specimen container
2. BCarry-over of tissue on the flotation water bath
3. CFixation of the biopsy in unbuffered formalin
4. DMetaplasia of the cervical epithelium to colonic type
Answer and explanation in LearnFree account

Museum technique, quality and safety in histopathology

At the end of a day in a Kerala histopathology laboratory, these items must be segregated under the Bio-Medical Waste Management Rules 2016: used microtome blades, broken glass slides, formalin-fixed tissue trimmings and used nitrile gloves. Which segregation is correct?

In the Kaiserling method of museum specimen preparation, the fixed specimen is moved into 80 to 95% ethanol (Kaiserling II). This step:

For quality control of a special stain, which is the best positive control section?

Sodium dithionite (sodium hydrosulphite) is added to some museum mounting fluids. What is its purpose?

During a stock check, a technologist finds an old bottle of picric acid at the back of a cupboard. The contents look dry, and yellow crystals are crusted around the screw cap. What should be done?

A lung removed at autopsy is to be preserved as a museum specimen. What is the best way to fix it?

What is the Gough-Wentworth technique used to prepare?

A whole brain removed at autopsy is to be fixed for the museum without flattening its shape. The usual way is to:

In the Kaiserling method, the final mounting fluid (Kaiserling III) keeps the specimen moist and clear mainly because it contains:

A Perls' Prussian blue run uses a liver section with known haemosiderosis as control. The control shows no blue granules, and a bone marrow clot section from a patient with suspected iron overload is also negative. What is the correct action?

A technologist needs to take a block out of the chuck of a rotary microtome. What should be done first?

A 900 mL spleen is to be fixed for the museum in 10% formalin, using a fixative volume 10 times that of the specimen. Stock formalin is 40% formaldehyde. How much stock formalin is needed?

On a section from a cervical biopsy, a small fragment of colonic mucosa lies at the edge of the slide, separate from the biopsy and outside its plane of section. The most likely source is: