ISBN-13: 9780130833310 978-0130833310
Chapter 3 – Testbank Multiple-Choice Questions
1. In transfusion medicine, the antihuman globulin (AHG) technique is used for numerous purposes including
a. Analyzing DNA
b. Detecting unexpected antibodies
c. Diagnosing the presence of human globulin
d. Inspecting microorganisms
2. The antihuman globulin technique is used to detect which isotype of antibody?
3. When the body first encounters a foreign antigen, a primary immune response is stimulated. One of the residual effects of the primary response is the retention of which memory cells?
4. ______ is the first immunoglobulin class produced in a primary immune response.
5. All of the following are characteristics of IgG except
a. Demonstrates agglutination in antiglobulin tests
b. Has a plasma half-life of about 23 days
c. Has a valence of 10
d. Is able to cross the placenta
6. Which of the following does not activate complement?
7. Antihuman globulin (AHG) reagent must contain anti-_____ when used for antibody detection.
8. Which of the following would be a disadvantage to using a monoclonal reagent?
a. No contaminating antibodies
b. Small variation between batches
c. Specificity may be relative
d. Unlimited production
9. All of the following statements are true regarding the indirect antiglobulin test (IAT) except
a. Begins with a source of antigen and antibody being added to the test system
b. Consists of a two-step method
c. Has a first step where anti-IgG attaches to any IgG coating the red blood cells
d. Is a very versatile test within the blood bank laboratory
10. Which of the following tests does not detect antibodies to red blood cell antigens?
a. Antibody screen
b. Antibody identification
c. Antigen typing
11. The primary purpose of the immediate spin phase is to detect antibodies that react at room temperature, typically antibodies of the _____ class.
12. When grading agglutination in a gel microtubule system, which grade is described as cells and agglutinates distributed through the column?
13. During the incubation phase of an antibody screen test, how long should the test tubes be incubated?
a. 5–10 minutes
b. 10–30 minutes
c. Depends on the temperature of incubation
d. Depends on the enhancement reagent added
14. During the AHG phase of an antibody screen test, before adding AHG reagent to the test tubes, what should the red blood cells be washed with?
a. Distilled water
15. The most common cause for the check cells not reacting is
a. Incorrect use of tubes
b. Improper washing
c. Malfunctioning equipment
d. Too much time in the centrifuge
16. _________ is typically added before the incubation phase of the antibody screen test.
17. Antibody screen tests must include an incubation step at what temperature, which is the optimal reaction temperature for IgG antibodies?
a. 39.2° F (4° C)
b. 71.6° F (22° C)
c. 91.4° F (33° C)
d. 98.6° F (37° C)
18. For tube testing, the most commonly used plasma-to-cell ratio is
a. One drop of plasma and one drop of 5% suspension of red blood cells
b. One drop of plasma and two drops 5% suspension of red blood cells
c. Two drops of plasma and one drop of 5% suspension of red blood cells
d. Two drops of plasma and two drops of 5% suspension of red blood cells
19. All of the following are true regarding the direct antiglobulin test (DAT) except
a. Detects sensitization in vivo of red blood cells with antibody or complement
b. Is performed in order to visualize antigen–antibody reactions that happened in the body, not the test tube
c. Is usually included in routine pretransfusion testing
d. Omits the incubation at 98.6° F (37° C) phase
20. All of the following can cause false results in both an indirect (IAT) or direct (DAT) antiglobulin test except
a. Contaminated saline
b. Inadequate incubation
c. Interruption in testing
d. Improper centrifugation