Immunohistochemistry Quizzes for Medical Students

Question 1

Which advantage makes immunohistochemistry superior to conventional histology staining in immunology research?

Accepted Answer

Precise identification of specific proteins within cells and tissues

Answer

Faster and more cost-effective alternative to histology staining

Answer

More comprehensive view of anatomical structures

Answer

Exclusively applicable to fresh tissue specimens

Question 2

What is the primary purpose of using a chromogen in immunohistochemistry?

Accepted Answer

To visualize the target antigens

Answer

To enhance the signal of bound antibodies

Answer

To block non-specific binding

Answer

To fix the tissue sample

Question 3

Which type of antibody is most commonly employed in immunohistochemistry?

Accepted Answer

Monoclonal antibodies

Answer

Polyclonal antibodies

Answer

Humanized antibodies

Answer

Fab antibody fragments

Question 4

What is the primary goal of heat-induced epitope retrieval in immunohistochemistry?

Accepted Answer

To enhance antigen accessibility within tissues

Answer

To inhibit the non-specific binding of antibodies

Answer

To protect target antigens from degradation

Answer

To increase the affinity of antibodies to their antigens

Question 5

What is the primary purpose of a counterstaining step in an immunohistochemistry protocol?

Accepted Answer

To provide structural context for interpreting the immunohistochemical staining

Answer

To visualize non-target tissues or structures

Answer

To enhance the staining of target antigens

Answer

To block non-specific background staining

Question 6

What is a key advantage of using chromogenic chromogens in immunohistochemistry compared to fluorescent chromogens?

Accepted Answer

Permanent visualization of the stain for long-term storage

Answer

Enhanced signal intensity for improved image analysis

Answer

Reduced background staining, leading to clearer images

Answer

Lower cost, making it more accessible

Question 7

Which type of tissue sample is typically less suitable for immunohistochemistry due to poor preservation of antigens?

Accepted Answer

Ethanol-fixed tissue

Answer

Formalin-fixed, paraffin-embedded tissue

Answer

Frozen tissue

Answer

Decalcified tissue

Question 8

What is the main difference between direct and indirect immunohistochemistry methods in terms of their experimental procedures?

Accepted Answer

The varying number of antibody incubation steps required

Answer

The types of antibodies utilized

Answer

The different types of chromogens employed

Answer

The varying accessibility of the target antigens

Question 9

How does immunohistochemistry aid in distinguishing between primary and metastatic tumors?

Accepted Answer

Immunohistochemistry can reveal the origin of metastatic tumors.

Answer

Immunohistochemistry is exclusively used to identify primary tumors.

Answer

Immunohistochemistry is not employed in cancer diagnosis.

Question 10

Which of the following is NOT a step in the standard immunohistochemistry (IHC) procedure?

Accepted Answer

Polymerase chain reaction (PCR)

Answer

Tissue fixation

Answer

Antigen retrieval

Answer

Antibody incubation

Question 11

What is the purpose of using a chromogen in IHC?

Accepted Answer

To visualize the antigen-antibody complex

Answer

To block non-specific background staining

Answer

To amplify the signal

Answer

To stain the nuclei of cells

Question 12

Which type of antigen retrieval is most commonly employed in immunohistochemistry?

Accepted Answer

Heat-induced epitope retrieval (HIER)

Answer

Microwave irradiation

Answer

Trypsin digestion

Answer

Chemical extraction

Question 13

The use of diaminobenzidine (DAB) as a chromogen typically results in a precipitate of what color?

Accepted Answer

Brown

Answer

Blue

Answer

Red

Answer

Black

Question 14

What is a key advantage of immunohistochemistry over in situ hybridization?

Accepted Answer

Better preservation of tissue morphology

Answer

Higher sensitivity

Answer

Lower cost

Answer

Faster results

Question 15

What is the main function of a blocking reagent in IHC?

Accepted Answer

To prevent non-specific antibody binding

Answer

To enhance antibody penetration

Answer

To label the secondary antibody

Answer

To amplify the chromogen signal

Question 16

Which of the following is NOT a step involved in immunohistochemistry?

Accepted Answer

Polymerase chain reaction (PCR)

Answer

Tissue fixation and processing

Answer

Antigen retrieval

Answer

Incubation with the primary antibody

Question 17

Which type of antibody is most commonly used in immunohistochemistry?

Accepted Answer

Monoclonal antibody

Answer

Polyclonal antibody

Answer

Fab fragment

Answer

Fc fragment

Question 18

What is the role of chromogen in immunohistochemistry?

Accepted Answer

To visualize the antibody-antigen reaction by producing a colored precipitate

Answer

To amplify the signal

Answer

To block nonspecific antibody binding

Answer

To enhance tissue adhesion

Question 19

What is the principle behind the use of a counterstain in immunohistochemistry?

Accepted Answer

To provide contrast and improve visualization of tissue structures

Answer

To block nonspecific antibody binding

Answer

To enhance the signal

Answer

To amplify the antibody-antigen reaction

Question 20

Which of the following is NOT a type of immunohistochemistry-based multiplex assay?

Accepted Answer

Polymerase chain reaction (PCR)

Answer

Tyramide signal amplification (TSA)

Answer

Multiplex immunofluorescence

Answer

Sequential staining

Question 21

What is the main advantage of immunohistochemistry over routine histological staining?

Accepted Answer

Localization of specific antigens

Answer

Rapid processing time

Answer

Enhanced image resolution

Answer

No need for tissue sectioning

Question 22

Which of the following is a commonly used chromogen in immunohistochemistry, producing a brown precipitate?

Accepted Answer

Diaminobenzidine (DAB)

Answer

Fast Red

Answer

Alkyl phosphatase

Answer

Horseradish peroxidase

Question 23

What is the purpose of the blocking step in immunohistochemistry?

Accepted Answer

Suppress non-specific antibody binding

Answer

Enhance the visibility of positive signals

Answer

Increase the sensitivity of the staining

Answer

Remove excess unbound antibodies

Question 24

What is the significance of antigen retrieval in immunohistochemistry for formalin-fixed tissues?

Accepted Answer

Improves the accessibility of masked antigens

Answer

Increases the specificity of staining

Answer

Reduces background staining

Answer

Preserves tissue morphology

Question 25

Which technique is NOT employed in the immunohistochemistry process?

Accepted Answer

Polymerase chain reaction (PCR)

Answer

Antigen retrieval

Answer

Immunoperoxidase staining

Answer

Chromogen development

Question 26

What is the primary purpose of the antigen retrieval step in immunohistochemistry?

Accepted Answer

To expose concealed antigens

Answer

To remove excess antibodies

Answer

To amplify the antigen signal

Answer

To block nonspecific binding

Question 27

Which enzyme is commonly utilized in immunoperoxidase staining to visualize antigens?

Accepted Answer

Horseradish peroxidase

Answer

Alkaline phosphatase

Answer

Beta-galactosidase

Answer

Luciferase

Question 28

What type of chromogen is typically employed to generate a brown precipitate in immunohistochemistry?

Accepted Answer

Diaminobenzidine (DAB)

Answer

Nitroblue tetrazolium (NBT)

Answer

5-bromo-4-chloro-3-indolyl phosphate (BCIP)

Answer

Fast red

Question 29

Which feature distinguishes immunohistochemistry from other diagnostic techniques?

Accepted Answer

Precise localization of antigens in tissues and cells

Answer

High sensitivity and specificity

Answer

Cost-effectiveness

Answer

Rapid turnaround time

Question 30

Why is the use of appropriate positive and negative controls essential in immunohistochemistry?

Accepted Answer

To ensure reliability and specificity of staining results

Answer

To calibrate staining intensity

Answer

To minimize background staining

Answer

To prevent false-positive results

Question 31

Which microscopy technique is typically used to examine immunohistochemistry slides?

Accepted Answer

Light microscopy

Answer

Electron microscopy

Answer

Confocal microscopy

Answer

Scanning probe microscopy

Question 32

In immunohistochemistry, the choice of primary antibody primarily considers:

Accepted Answer

Target antigen's specificity

Answer

Species of tissue being stained

Answer

Staining technique being used

Question 33

Which technique is commonly used in immunohistochemistry to amplify the signal for enhanced antigen visualization?

Accepted Answer

Biotin-streptavidin system

Answer

Polymerase chain reaction (PCR)

Question 34

The term 'epitope' refers to:

Accepted Answer

The site on an antigen recognized by a specific antibody

Answer

The entire sequence of an antigen

Question 35

In immunohistochemistry, tissue controls are crucial for:

Accepted Answer

Assessing antibody specificity

Answer

Evaluating staining intensity

Question 36

What is the primary function of a counterstain in immunohistochemistry?

Accepted Answer

Visualizing nuclei

Answer

To enhance antigen visualization

Question 37

Which of the following is absent in the immunohistochemistry (IHC) process?

Accepted Answer

Polymerase chain reaction (PCR)

Answer

Antigen retrieval

Answer

Immunoperoxidase staining

Answer

Chromogen development

Question 38

In IHC, the primary antibody specifically recognizes and binds to:

Accepted Answer

Target antigen

Answer

Secondary antibody

Answer

Enzyme conjugate

Answer

Chromogen

Question 39

Which antigen retrieval technique is most commonly employed for tissue sections?

Accepted Answer

Any of the above

Answer

Enzymatic digestion

Answer

Microwave heating

Answer

Pressure cooking

Question 40

In IHC, the chromogen serves as the:

Accepted Answer

Colored substrate

Answer

Enzyme

Answer

Antibody

Answer

Antigen

Question 41

Which of the following can compromise the specificity of an immunohistochemical stain?

Accepted Answer

Any of the above

Answer

Cross-reactivity of antibodies

Answer

Background staining

Answer

Non-specific binding

Question 42

In IHC, the enzyme conjugate's primary function is to:

Accepted Answer

Catalyze chromogen conversion

Answer

Bridge primary and secondary antibodies

Answer

Amplify the signal

Answer

Bind to the antigen

Question 43

Which of the following is NOT a typical step in the immunohistochemistry (IHC) staining protocol?

Accepted Answer

Antigen precipitation

Answer

Primary antibody incubation

Answer

Secondary antibody incubation

Answer

Antigen retrieval

Question 44

In IHC, the primary antibody specifically binds to which component of the antigen?

Accepted Answer

Epitope

Answer

Paratope

Answer

CDR3

Question 45

Which enzyme is most commonly used as a chromogen in IHC?

Accepted Answer

Horseradish peroxidase (HRP)

Answer

Glucose oxidase (GOx)

Answer

Beta-galactosidase (LacZ)

Answer

Alkaline phosphatase (ALP)

Question 46

What is the primary application of IHC in diagnostic pathology?

Accepted Answer

Identifying specific protein expression in tissues

Answer

Detecting circulating antigens

Answer

Quantitating gene expression levels

Question 47

What is a major advantage of immunofluorescence (IF) over IHC in certain applications?

Accepted Answer

Simultaneous visualization of multiple antigens

Answer

Fewer background staining issues

Answer

Improved tissue preservation

Answer

Higher sensitivity than IHC

Question 48

Which of the following is NOT a step in the immunohistochemical staining process?

Accepted Answer

Cell dehydration

Answer

Chromogen application

Answer

Antigen retrieval

Answer

Antibody incubation

Question 49

What is the primary function of the peroxidase enzyme in immunohistochemistry?

Accepted Answer

Catalyzes the conversion of chromogen to a colored product

Answer

Binds to the primary antibody

Answer

Enhances antigen-antibody binding

Question 50

What is the purpose of antigen retrieval in immunohistochemistry?

Accepted Answer

To expose hidden antigens for antibody binding

Answer

To reduce background staining

Answer

To amplify the signal of bound antibodies

Answer

To enhance antibody specificity

Question 51

What is the main advantage of using chromogenic substrates in immunohistochemistry?

Accepted Answer

Permanent visualization of antigens in tissue sections

Answer

High sensitivity and specificity

Answer

Ability to perform multiplexing

Question 52

Which of the following is a quantitative method for assessing protein expression using immunohistochemistry?

Accepted Answer

Image analysis

Answer

Western blotting

Answer

Immunoelectron microscopy

Answer

Flow cytometry

Question 53

What is the clinical significance of immunohistochemistry in diagnostic pathology?

Accepted Answer

Identifies disease biomarkers, aids in diagnosis, and guides treatment decisions

Answer

Provides detailed information on tissue architecture

Answer

Assesses gene expression levels