Calcofluor White Staining MCQs Mock Test

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Master fungal diagnostics with our ultimate Calcofluor White Staining resource! This comprehensive guide includes:

🔍 50 Essential FAQs Covering:
✓ Principle: How Calcofluor binds to fungal chitin/cellulose
✓ Protocol: Step-by-step staining for Candida, Aspergillus, Pneumocystis
✓ Microscopy: Optimal UV filter sets (DAPI vs. FITC)
✓ Troubleshooting: Background fluorescence, false positives
✓ Clinical Apps: Rapid fungal detection in KOH mounts

📝 30 Challenging MCQs On:
◼️ Stain preparation (KOH/CFW ratios)
◼️ Distinguishing hyphae vs. pseudohyphae
◼️ Artifact identification (cotton fibers, starch)
◼️ Comparison to PAS/GMS stains

🎯 Perfect For:
• Medical mycologists • Clinical lab technicians • USMLE/PLAB aspirants

Includes detailed explanations and reference images!

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Microbiology Department

Calcofluor White Staining MCQs Mock Test

Master fungal diagnostics with our ultimate Calcofluor White Staining resource! This comprehensive guide includes:

Read Full Article: Calcofluor White Staining FAQs and MCQs

1 / 30

Category: Clinical Laboratory

Which of these is a non-fungal application of Calcofluor White?

Viral culture

Textile brightening agent

Gram staining

Acid-fast bacilli detection

2 / 30

Category: Clinical Laboratory

Which component of fungal cell walls binds Calcofluor White?

Phospholipids

Ergosterol

Chitin

Mannoproteins

3 / 30

Category: Clinical Laboratory

What does Calcofluor White primarily bind to?

Proteins

Chitin and cellulose

DNA

Lipids

4 / 30

Category: Clinical Laboratory

Which of the following is NOT detected by Calcofluor White?

Bacterial cells

Acanthamoeba cysts

Pneumocystis jirovecii

Candida albicans

5 / 30

Category: Clinical Laboratory

What is a major limitation of this technique?

Only works on bacteria

Cannot detect yeast

Takes 24 hours for results

Requires a fluorescent microscope

6 / 30

Category: Clinical Laboratory

What is the main advantage of Calcofluor White Staining?

Cheaper than KOH

Stains only dead cells

Rapid detection of fungi/parasites

Works without a microscope

7 / 30

Category: Clinical Laboratory

Which fungal infection is rapidly diagnosed using Calcofluor White?

Tuberculosis

Hepatitis B

Onychomycosis

Malaria

8 / 30

Category: Clinical Laboratory

Which light source is LEAST effective for Calcofluor excitation?

Blue-violet light

Violet light

Red light

UV light

9 / 30

Category: Clinical Laboratory

Which industry uses Calcofluor White as a fabric whitener?

Automotive

Pharmaceutical

Textile

Food

10 / 30

Category: Clinical Laboratory

Which organism’s TROPHOZOITES do NOT fluoresce with Calcofluor White?

Aspergillus

Acanthamoeba

Candida

Cryptococcus

11 / 30

Category: Clinical Laboratory

What color do fungi fluoresce under UV light with Calcofluor White?

Yellow

Apple-green

Red

Blue

12 / 30

Category: Clinical Laboratory

Which of the following is a false-positive artifact in Calcofluor White Staining?

Cotton fibers

Pneumocystis cysts

Fungal hyphae

Candida cells

13 / 30

Category: Clinical Laboratory

What is the size range of Pneumocystis cysts observed with Calcofluor White?

1–2 µm

20–30 µm

10–15 µm

5–8 µm

14 / 30

Category: Clinical Laboratory

Why is KOH often preferred over Calcofluor White in some labs?

Works faster (5 seconds)

Lower cost and no need for a fluorescent microscope

Doesn’t require a coverslip

Better for bacterial staining

15 / 30

Category: Clinical Laboratory

What is added to Calcofluor White for clearing debris in skin/nail samples?

Ethanol

NaCl

HCl

10% KOH

16 / 30

Category: Clinical Laboratory

What is the emission peak wavelength of Calcofluor White?

475 nm (apple-green)

600 nm

700 nm

300 nm

17 / 30

Category: Clinical Laboratory

What structure in yeast is intensely stained by Calcofluor White?

Bud scars

Nucleus

Mitochondria

Ribosomes

18 / 30

Category: Clinical Laboratory

Which fungal structure does NOT stain with Calcofluor White?

Yeast cells

Pseudohyphae

Ascospores

Hyphae

19 / 30

Category: Clinical Laboratory

Why is Calcofluor White used in Papanicolaou (Pap) smears?

To stain nuclei

To fix cells

To enhance yeast cell visibility

To detect HPV

20 / 30

Category: Clinical Laboratory

Why do cotton fibers interfere with interpretation?

They inhibit fungal growth

They fluoresce strongly (cellulose content)

They dissolve in KOH

They turn black

21 / 30

Category: Clinical Laboratory

Which counterstain reduces background fluorescence in Calcofluor White?

Methylene blue

Iodine

Safranin

Evans Blue

22 / 30

Category: Clinical Laboratory

Which parasite’s cysts are detected by Calcofluor White?

Acanthamoeba

Entamoeba histolytica

Giardia

Plasmodium

23 / 30

Category: Clinical Laboratory

Why is Evans Blue used as a counterstain?

To dissolve chitin

To kill microbes

To reduce background fluorescence

To enhance fungal growth

24 / 30

Category: Clinical Laboratory

How long should the stain be left before observation?

30 minutes

1 minute

1 hour

10 seconds

25 / 30

Category: Clinical Laboratory

Which type of microscope is required for Calcofluor White Staining?

Fluorescent

Phase-contrast

Brightfield

Electron

26 / 30

Category: Clinical Laboratory

What is the optimal magnification for observing Calcofluor White-stained samples?

100X–400X

1000X

40X

2000X

27 / 30

Category: Clinical Laboratory

What does apple-green fluorescence indicate in a BAL sample?

Red blood cells

Epithelial cells

Bacteria

Pneumocystis cysts

28 / 30

Category: Clinical Laboratory

What is the shelf life of properly stored Calcofluor White Stain?

10 years

1 week

1 month

1 year

29 / 30

Category: Clinical Laboratory

Which wavelength is best for exciting Calcofluor White?

550 nm

200 nm

347 nm (UV light)

700 nm

30 / 30

Category: Clinical Laboratory

How should Calcofluor White Stain be stored?

Under vacuum

Frozen

In direct sunlight

At room temperature, protected from light

Your score is

The average score is 67%

Read Full Article: Calcofluor White Staining FAQs and MCQs

“Best stain for Pneumocystis in BAL samples”
“Calcofluor vs. KOH sensitivity comparison”
“How to reduce background fluorescence in CFW”
“Fungal hyphae identification MCQs”

Possible References Used

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