Negative staining of Viruses MCQs Mock Test (30 MCQs)

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Prepare for your virology and microbiology exams with our 30 Negative Staining of Viruses MCQs Mock Test on LabTestsGuide.com! This quiz is designed to test your knowledge of electron microscopy (EM) techniques used in virus visualization, including:

Principle of negative staining (phosphotungstic acid, uranyl acetate)
Virus morphology identification (enveloped vs. non-enveloped, capsid symmetry)
Commonly studied viruses (Herpesviruses, Influenza, Bacteriophages)
Artifacts and troubleshooting in EM sample preparation

Perfect for medical students, virologists, microbiologists, and lab technicians preparing for board exams, certifications, and research applications.

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Hematology Department

Negative Staining of Viruses MCQs Mock Test

- Principle of negative staining (phosphotungstic acid, uranyl acetate)

- Virus morphology identification (enveloped vs. non-enveloped, capsid symmetry)

- Commonly studied viruses (Herpesviruses, Influenza, Bacteriophages)

- Artifacts and troubleshooting in EM sample preparation

Perfect for medical students, virologists, microbiologists, and lab technicians preparing for board exams, certifications, and research applications

Read Full Article: Negative staining of Viruses 50 FAQ and 30 MCQs

1 / 30

Category: Clinical Laboratory

Negative staining is particularly useful for studying:

Only bacterial cells

Viruses and bacterial surface structures

Only plant tissues

Fungal spores

2 / 30

Category: Clinical Laboratory

What artifact can occur due to superimposed staining layers?

Acid-fast staining

Moiré pattern

Fluorescence quenching

Gram-positive reaction

3 / 30

Category: Clinical Laboratory

Negative staining is most useful for:

Rapid preliminary virus identification

Quantifying viral load

DNA extraction

Culturing viruses

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Category: Clinical Laboratory

How does negative staining create contrast in TEM images?

By staining the virus directly

By amplifying viral RNA

By using antibodies

By absorbing electrons in the stained background

5 / 30

Category: Clinical Laboratory

Why might some viruses appear “collapsed” in TEM?

Due to one-sided staining

Due to over-staining

Because of high pH

Due to freeze-thawing

6 / 30

Category: Clinical Laboratory

In negative staining, how do viruses appear under TEM?

Invisible

Fluorescent green

Dark against a light background

Light against a dark background

7 / 30

Category: Clinical Laboratory

15. What is used to remove excess stain from the grid?

Heat fixation

Alcohol wash

Centrifugation

Filter paper wicking

8 / 30

Category: Clinical Laboratory

Why is ammonium molybdate preferred for large viruses?

It binds tightly to the support film

It is radioactive

It stains nucleic acids

It works only at high pH

9 / 30

Category: Clinical Laboratory

Which virus is best studied with ammonium molybdate staining?

HIV

Rabies

Hepatitis B

Influenza (Orthomyxovirus)

10 / 30

Category: Clinical Laboratory

What viral feature is commonly observed in adenovirus after negative staining?

Long fibers and penton bases

Capsid symmetry

Lipid blebs

Double-stranded DNA

11 / 30

Category: Clinical Laboratory

Why is negative staining disappearing from mainstream use?

It requires radioactive stains

It cannot stain bacteria

It is too expensive

Advanced techniques (e.g., cryo-EM) offer better resolution

12 / 30

Category: Clinical Laboratory

Which stain is commonly used for enveloped viruses due to its low pH?

Uranyl acetate

Ammonium molybdate

Sodium silicotungstate (SST)

Phosphotungstic acid

13 / 30

Category: Clinical Laboratory

What is “immuno-negative staining”?

A DNA sequencing method

A fluorescence technique

Combining antibodies with negative staining

A type of Gram staining

14 / 30

Category: Clinical Laboratory

Who first introduced negative staining?

Brenner and Horne (1959)

Antonie van Leeuwenhoek

Louis Pasteur

Robert Koch

15 / 30

Category: Clinical Laboratory

Which of the following is NOT an application of negative staining?

Diagnosing bacterial infections

Studying viral morphology

Sequencing viral RNA

Visualizing bacterial flagella

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Category: Clinical Laboratory

What happens if too much stain is left on the grid?

Only stain is visible, obscuring the virus

The virus appears brighter

The grid becomes hydrophobic

The virus disintegrates

17 / 30

Category: Clinical Laboratory

What is the ideal concentration range for most viruses in negative staining?

50–100 mg/ml

10–20 mg/ml

1–5 mg/ml

0.05–0.1 mg/ml

18 / 30

Category: Clinical Laboratory

What does orthomyxovirus (e.g., influenza) show in negative staining?

Thick cell wall

Flagella

Helical nucleic acid

Spiked surface (hemagglutinin)

19 / 30

Category: Clinical Laboratory

What is the pH of uranyl acetate?

7.0 (neutral)

4.4 (acidic)

9.2 (basic)

2.0 (highly acidic)

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Category: Clinical Laboratory

What is the primary purpose of negative staining in electron microscopy?

To increase virus infectivity

To stain the background while leaving the virus unstained

To stain the virus itself

To fix the viral nucleic acids

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Category: Clinical Laboratory

Which safety precaution is necessary when handling uranyl acetate?

Avoiding water contact

Wearing gloves and a lab coat

Using a fume hood

Keeping it frozen

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Category: Clinical Laboratory

What type of stains are used in negative staining?

Heavy metal salts (e.g., uranium, tungsten)

Basic dyes

Methylene blue

Fluorescent dyes

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Category: Clinical Laboratory

Why is carbon film preferred over plastic film?

It provides better adsorption and contrast

It fluoresces under UV

It is hydrophobic

It is cheaper

24 / 30

Category: Clinical Laboratory

Which support film is preferred for negative staining?

Gold film

Plastic film

Carbon film

Glass slide

25 / 30

Category: Clinical Laboratory

How long should uranyl acetate be stirred before use?

24 hours

1–2 minutes

30 minutes to 1 hour

Not required

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Category: Clinical Laboratory

What is a major problem during air-drying of enveloped viruses?

They dissolve in the stain

They multiply rapidly

They become positively stained

They flatten and lose structure

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Category: Clinical Laboratory

What is a limitation of negative staining?

It can distort fragile viruses

It only works for fungi

It requires live viruses

It cannot be used with TEM

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Category: Clinical Laboratory

Which microscope is most commonly used for negative staining of viruses?

Transmission Electron Microscope (TEM)

Fluorescence microscope

Light microscope

Scanning Electron Microscope (SEM)

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Category: Clinical Laboratory

What is a disadvantage of uranyl acetate?

It cannot be filtered

It produces low contrast

It only works for non-enveloped viruses

It can be radioactive

30 / 30

Category: Clinical Laboratory

Which stain is chemically inert and has a neutral pH?

Crystal violet

Methylene blue

Sodium silicotungstate

Uranyl acetate

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The average score is 37%

Read Full Article: Negative staining of Viruses 50 FAQ and 30 MCQs

“Best MCQs on negative staining for TEM”
“How to identify virus morphology using EM”
“Phosphotungstic acid vs. uranyl acetate staining”
“Electron microscopy virus detection quiz”

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