Grocott-Gomori’s Methenamine Silver Staining

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Explore Grocott-Gomori’s Methenamine Silver (GMS) Staining, a key histopathological technique used to detect fungal infections (e.g., Pneumocystis, Aspergillus, Candida) and some basement membrane components. This guide covers its principle, procedure, interpretation, and clinical significance—essential for pathologists, microbiologists, and lab professionals.

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Grocott-Gomori’s Methenamine Silver Staining MCQs Mock Test

Read Full Article: Grocott-Gomori’s Methenamine Silver Stain 50 FAQ and 40 MCQs

1 / 30

Category: Clinical Laboratory

Which step is unique to microwave GMS staining?

Heating chromic acid for 2.5 minutes

Freezing slides

Using a water bath

Overnight incubation

2 / 30

Category: Clinical Laboratory

Which fixative is optimal for GMS?

10% formalin

Acetone

Bouin’s solution

95% ethanol

3 / 30

Category: Clinical Laboratory

What indicates a successful GMS control slide?

Blue nuclei

Clear unstained fungi

Black fungal elements

Uniform green background

4 / 30

Category: Clinical Laboratory

How are hyphae visualized in GMS?

Black walls, pink interiors

Red walls, green interiors

Blue walls, clear interiors

Unstained

5 / 30

Category: Clinical Laboratory

What indicates proper silver impregnation?

Slides turn blue

Slides turn red

Slides become transparent

Slides turn yellowish-brown

6 / 30

Category: Clinical Laboratory

What is the primary purpose of GMS staining?

Identifying fungal cell walls

Highlighting collagen fibers

Detecting bacterial infections

Staining viral particles

7 / 30

Category: Clinical Laboratory

Which component of the fungal cell wall reacts with GMS stain?

Polysaccharides

Nucleic acids

Proteins

Lipids

8 / 30

Category: Clinical Laboratory

What causes tissue to detach during staining?

Skipping the gold step

Insufficient dehydration

Over-oxidation

Using tap water

9 / 30

Category: Clinical Laboratory

What wattage is used for microwave silver incubation?

450W

50W

1000W

150W

10 / 30

Category: Clinical Laboratory

Which step is skipped in microwave GMS vs. conventional?

Silver incubation

Chromic acid oxidation

None—steps are identical

Gold toning

11 / 30

Category: Clinical Laboratory

What is the role of sodium metabisulfite in GMS?

Counterstain

Oxidizing agent

Toning agent

Reducing agent

12 / 30

Category: Clinical Laboratory

Which PPE is mandatory for GMS staining?

Goggles, gloves, lab coat, fume hood

No special precautions

Gloves only

Lab coat and gloves

13 / 30

Category: Clinical Laboratory

How long can methenamine silver stock solution be stored?

Indefinitely

3 months (refrigerated)

1 year

1 week

14 / 30

Category: Clinical Laboratory

Which fungus is commonly detected using GMS in immunocompromised patients?

Herpes simplex virus

Escherichia coli

Mycobacterium tuberculosis

Pneumocystis jiroveci

15 / 30

Category: Clinical Laboratory

What is a drawback of microwave GMS?

Weaker staining

Higher cost

Inconsistent heating

Longer procedure

16 / 30

Category: Clinical Laboratory

What does mucin look like in GMS-stained sections?

Dark grey

Pink-red

Green

Black

17 / 30

Category: Clinical Laboratory

Which chemical oxidizes polysaccharides in GMS staining?

Methenamine

Chromic acid

Sodium thiosulfate

Gold chloride

18 / 30

Category: Clinical Laboratory

Why use plastic Coplin jars in microwave GMS?

Better staining

Cheaper than glass

Faster heating

Prevents metal interference

19 / 30

Category: Clinical Laboratory

What color do fungi appear after GMS staining?

Black

Green

Blue

Red

20 / 30

Category: Clinical Laboratory

Why is borax added to the silver solution?

Prevents precipitation

Accelerates oxidation

Lowers pH

Acts as a buffer

21 / 30

Category: Clinical Laboratory

Which counterstain is used in GMS to highlight the background?

Eosin

Light green SF yellowish

Hematoxylin

Methylene blue

22 / 30

Category: Clinical Laboratory

What is the purpose of sodium thiosulfate?

Counterstain nuclei

Oxidize fungi

Enhance gold toning

Remove unbound silver

23 / 30

Category: Clinical Laboratory

How should silver nitrate waste be handled?

Dispose as hazardous waste

Reuse for future stains

Incinerate immediately

Pour down the sink

24 / 30

Category: Clinical Laboratory

Which stain is more sensitive for fungi than GMS?

H&E

PAS (Periodic Acid-Schiff)

None—GMS is the most sensitive

Gram stain

25 / 30

Category: Clinical Laboratory

What hazard is associated with chromic acid?

Flammable

Explosive

Corrosive and carcinogenic

Radioactive

26 / 30

Category: Clinical Laboratory

Which organism is GMS-negative?

Toxoplasma gondii

Candida

Aspergillus

Histoplasma

27 / 30

Category: Clinical Laboratory

How long should slides remain in chromic acid (conventional method)?

5 minutes

1 hour

2 hours

30 minutes

28 / 30

Category: Clinical Laboratory

Which reagent tones the sections to improve contrast?

Borax

Gold chloride

Light green

Silver nitrate

29 / 30

Category: Clinical Laboratory

Why might fungi fail to stain black?

Overuse of light green

Insufficient dehydration

Excessive gold toning

Old chromic acid

30 / 30

Category: Clinical Laboratory

How long is chromic acid microwaved in the modified protocol?

30 seconds

1 hour

10 minutes

2.5 minutes

Your score is

The average score is 0%

Read Full Article: Grocott-Gomori’s Methenamine Silver Stain 50 FAQ and 40 MCQs

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