Ch. 5 The Antiglobulin Test Pg. 116 Textbook Questions
14. Which factor can affect AHG testing, yet is uncontrollable in the lab? a. Temperature b. Antibody affinity c. Gravitational force in the centrifuge d. Incubation time
b. Antibody affinity
16. A 27-year-old group O mother has just given birth to a beautiful, group A baby girl. Since the mother has IgG anti-A in her plasma, it is likely that the baby is experiencing some in vivo red cell destruction. Which of the following methods and tests would be most effective at detecting the anti-A on the baby's RBCs? a. DAT using common tube technique b. DAT using gel c. IAT using common tube technique d. IAT using gel
b. DAT using gel
1. A principle of the antiglobulin test is: a. IgG and C3d are required for RBC sensitization. b. Human globulin is eluted from RBCs during saline washings. c. Injection of human globulin into an animal engenders passive immunity. d. AHG reacts with human globulin molecules bound to RBCs or free in serum.
d. AHG reacts with human globulin molecules bound to RBCs or free in serum.
10. Solid-phase antibody screening is based on: a. Adherence. b. Agglutination. c. Hemolysis. d. Precipitation.
a. Adherence.
3. Monoclonal anti-C3d is: a. Derived from one clone of plasma cells. b. Derived from multiple clones of plasma cells. c. Derived from immunization of rabbits. d. Reactive with C3b and C3d.
a. Derived from one clone of plasma cells.
13. Which of the following methods requires the use of check cells? a. LISS b. Gel c. Solid-phase d. Enzyme-linked
a. LISS
8. False-positive DAT results are most often associated with: a. Use of refrigerated, clotted blood samples in which complement components coat RBCs in vitro. b. A recipient of a recent transfusion manifesting an immune response to recently transfused RBCs. c. Presence of heterophile antibodies from administration of globulin. d. A positive autocontrol caused by polyagglutination.
a. Use of refrigerated, clotted blood samples in which complement components coat RBCs in vitro.
6. RBCs must be washed in saline at least three times before the addition of AHG reagent to: a. Wash away any hemolyzed cells b. Remove traces of free serum globulins c. Neutralize any excess AHG reagent d. Increase the antibody binding to antigen
b. Remove traces of free serum globulins
5. After the addition of IgG-coated RBCs (check cells) to a negative AHG reaction during an antibody screen, a negative result is observed. Which of the following is a correct interpretation? a. The antibody screen is negative. b. The antibody screen needs to be repeated. c. The saline washings were adequate. d. Reactive AHG reagent was added.
b. The antibody screen needs to be repeated.
2. Polyspecific AHG reagent contains: a. Anti-IgG. b. Anti-IgG and anti-IgM. c. Anti-IgG and anti-C3d. d. Anti-C3d.
c. Anti-IgG and anti-C3d.
11. A positive DAT may be found in which of the following situations? a. A weak D-positive patient b. A patient with anti-K c. HDN d. An incompatible crossmatch
c. HDN
15. If you had the authority to decide which primary AHG methodology to utilize at your lab, which method would you choose based on the knowledge that the majority of the staff are generalists? a. LISS b. Polybrene c. Solid phase or gel d. Enzyme-linked
c. Solid phase or gel
12. What do Coombs' control cells consist of? a. Type A-positive cells coated with anti-D b. Type A-negative cells coated with anti-D c. Type O-positive cells coated with anti-D d. Type O-negative cells coated with anti-D
c. Type O-positive cells coated with anti-D
7. An in vitro phenomenon associated with a positive IAT is: a. Maternal antibody coating fetal RBCs b. Patient antibody coating patient RBCs c. Recipient antibody coating transfused donor RBCs d. Identification of alloantibody specificity using a panel of reagent RBCs
d. Identification of alloantibody specificity using a panel of reagent RBCs
