Question 1

Why is it important to match the lot number on the panel sheet with the lot number on the panel cells?
A) The ABO group will change from lot to lot.
B) Pattern of reactions will change from lot to lot.
C) It is a requirement of the FDA.
D) All of the above

Accepted Answer

The pattern of reactions can vary between different lots, so matching the lot numbers ensures consistency and accuracy in test results.

Question 2

How does LISS enhance antibody detection in the antibody screen?
A) Increases the incubation times, which increases the sensitivity of the test
B) Increases the zeta potential, promoting agglutination of sensitized red blood cells
C) Increases the rate at which antibody binds to red blood cell antigens
D) None of the above

Accepted Answer

LISS (Low Ionic Strength Solution) enhances antibody detection by increasing the rate at which antibodies bind to red blood cell antigens, thus promoting faster and more efficient agglutination reactions.

Question 3

What is an elution?
A) A technique used to dissociate IgM antibodies from sensitized RBCs
B) A technique used to dissociate IgG antibodies from sensitized RBCs
C) A technique used to reduce the zeta potential enhancing antigen binding
D) None of the above

Accepted Answer

Elution is a laboratory technique used to remove and recover IgG antibodies from the surface of sensitized red blood cells (RBCs).

Question 4

A positive autocontrol in antibody detection procedures is usually indicative of:
A) inadequate washing.
B) positive DAT.
C) positive IAT.
D) none of the above.

Accepted Answer

A positive autocontrol in antibody detection procedures typically indicates a positive Direct Antiglobulin Test (DAT), suggesting that antibodies are bound to the patient's own red blood cells.

Question 5

Which cells are employed to remove autoantibody from patient serum without removing any alloantibody from serum?
A) Coombs' control red blood cells
B) Screening red blood cells
C) Patient red blood cells
D) Panel red blood cells

Accepted Answer

Patient red blood cells are used to adsorb autoantibodies from the serum, allowing for the detection of alloantibodies that may be present.

Question 6

Why is an enzyme treatment used in antibody identification?
A) Enzymes aid in the dissociation of antibody from antigen in a positive DAT.
B) Enzymes aid in the separation and identification of multiple antibodies.
C) Enzymes aid in the absorption of autoantibody from patient serum.
D) Enzymes aid in the separation and identification of multiple antibodies and the absorption of autoantibody from patient serum.

Accepted Answer

Enzymes aid in the separation and identification of multiple antibodies and the absorption of autoantibody from patient serum.

Question 7

Which of the following high-frequency antigens do not cause in vivo red blood cell destruction when complexed with corresponding antibody? A) k B) Js^b C) Ch^a D) Lu^b

Accepted Answer

Ch^a is part of the Chido/Rodgers blood group system, which is associated with complement components rather than red blood cell antigens. Antibodies to Ch^a do not cause red blood cell destruction.

Question 8

Which of the following is a mechanism of an elution procedure?
A) Disruption of structural complementarity of antigen and antibody
B) Enhancement of structural complementarity of antigen and antibody
C) Exchange of one immunoglobulin class for another
D) Denaturation of membrane epitopes by chemical means

Accepted Answer

Elution procedures often involve disrupting the structural complementarity between the antigen and antibody to release the bound antibody from the antigen.

Question 9

A patient with a warm autoantibody has a positive DAT. The antibody screen was negative, but the eluate reacted uniformly with all normal cells and patient cells. Why was the antibody screen negative?
A) Reagent red blood cells were saturated with warm autoantibody from patient serum.
B) No alloantibodies were present.
C) The warm autoantibody has bound to patient RBCs in circulation.
D) Polyspecific AHG was used instead of monospecific IgG.

Accepted Answer

The answer of A patient with a warm autoantibody has...

Question 10

What screening cells are used primarily for testing donor units for unexpected antibodies?
A) Pooled
B) 2-vial
C) 3-vial
D) 4-vial

Accepted Answer

Pooled screening cells are used primarily for testing donor units for unexpected antibodies because they provide a broad range of antigenic profiles in a single test, making the process more efficient.

Question 11

When performing the elution procedure, the solution containing the recovered antibody is called:
A) neutralized serum.
B) the buffer.
C) the eluate.
D) absorbed serum.

Accepted Answer

The eluate is the solution that contains the recovered antibody after the elution procedure.

Question 12

The process of removing antibody from serum by combining a serum sample with appropriate red blood cells under optimal conditions is called:
A) elution.
B) absorption.
C) enzyme treatment.
D) sensitization.

Accepted Answer

Absorption is the process of removing antibodies from serum by combining it with red blood cells that have the corresponding antigens.

Question 13

Which of the following statements concerning acid eluates is false?
A) Citric acid is an example of an acid eluate.
B) The pH is reduced to 3 or less to disrupt the antigen-antibody complex.
C) The pH of the eluate remains at 3 before testing against a panel.
D) None of the above

Accepted Answer

The pH of the eluate is typically adjusted back to a neutral pH before testing against a panel, not kept at 3.

Question 14

What is the purpose of Coombs' control cells?
A) To ensure that AHG tests with negative results are not false-negatives
B) To ensure that washing removed all unbound antibody
C) To ensure that AHG was not omitted or inactivated
D) All of the above

Accepted Answer

Coombs' control cells are used to verify that the anti-human globulin (AHG) reagent is working properly, ensuring that negative results are not false-negatives, that washing removed unbound antibodies, and that AHG was not omitted or inactivated.

Question 15

Routine pretransfusion testing consists of all of the following except:
A) ABO typing.
B) Rh typing.
C) an antibody screen.
D) a DAT.

Accepted Answer

A Direct Antiglobulin Test (DAT) is not part of routine pretransfusion testing; it is used to detect antibodies bound to red blood cells in vivo, typically for diagnosing hemolytic anemia.

Question 16

What would be a realistic source of finding compatible units for a person with an antibody to a high-frequency antigen?
A) Random donor units
B) A donor of similar ethnic background
C) Siblings
D) Apheresis donors

Accepted Answer

The answer of What would be a realistic source of...

Question 17

In what test might rouleaux cause an interference?
A) DAT
B) Forward ABO grouping
C) Reverse ABO grouping
D) Rh control

Accepted Answer

Rouleaux formation can interfere with reverse ABO grouping because it can cause false agglutination reactions, leading to incorrect interpretation of blood type.

Question 18

In interpreting an antibody screen, which of the following questions might be asked to decipher the class of antibody?
A) Is the autologous control positive or negative?
B) Is hemolysis present?
C) In what phase did the reaction occur?
D) Is rouleaux present?

Accepted Answer

The phase in which the reaction occurs can help determine the class of antibody, as different classes react at different temperatures and phases (e.g., IgM typically reacts at room temperature, while IgG reacts at body temperature).

Question 19

Which of the following statements is correct concerning cold antibody screens?
A) Patient serum is incubated with group O adult and cord red blood cells at 4°C.
B) Patient serum is incubated with group O cord cells at 37°C.
C) Patient serum is incubated with check cells at 18°C.
D) Patient serum is incubated with group A cord cells at room temperature.

Accepted Answer

Cold antibody screens are typically performed by incubating patient serum with group O adult and cord red blood cells at 4°C to detect cold agglutinins.

Question 20

A person has developed an antibody to the LISS reagent. What test will not be affected by this circumstance?
A) Major ACT crossmatch
B) IAT
C) DAT
D) Antibody screen

Accepted Answer

The Direct Antiglobulin Test (DAT) does not use the LISS reagent, as it detects antibodies or complement bound to red blood cells in vivo, not requiring enhancement media like LISS.

Quiz 10: Detection and Identification of Antibodies

Why is it important to match the lot number on the panel sheet with the lot number on the panel cells?

How does LISS enhance antibody detection in the antibody screen?

What is an elution?

A positive autocontrol in antibody detection procedures is usually indicative of:

Which cells are employed to remove autoantibody from patient serum without removing any alloantibody from serum?

Why is an enzyme treatment used in antibody identification?

Which of the following high-frequency antigens do not cause in vivo red blood cell destruction when complexed with corresponding antibody?

Which of the following is a mechanism of an elution procedure?

A patient with a warm autoantibody has a positive DAT. The antibody screen was negative, but the eluate reacted uniformly with all normal cells and patient cells. Why was the antibody screen negative?

What screening cells are used primarily for testing donor units for unexpected antibodies?

When performing the elution procedure, the solution containing the recovered antibody is called:

The process of removing antibody from serum by combining a serum sample with appropriate red blood cells under optimal conditions is called:

Which of the following statements concerning acid eluates is false?

What is the purpose of Coombs' control cells?

Routine pretransfusion testing consists of all of the following except:

What would be a realistic source of finding compatible units for a person with an antibody to a high-frequency antigen?

In what test might rouleaux cause an interference?

In interpreting an antibody screen, which of the following questions might be asked to decipher the class of antibody?

Which of the following statements is correct concerning cold antibody screens?

A person has developed an antibody to the LISS reagent. What test will not be affected by this circumstance?