CLS 422 Clinical Immunohematology I Take Home Quiz Day Two ...

11. What is the advantage of lowering the zeta potential in the antibody screen
procedure?
a. Allows RBCs to draw closer together so agglutination can occur
b. Decreases the sensitivity of the test system
c. Eliminates detection of naturally occurring antibodies
d. Increases the possibility of detecting an IgM antibody
12. When performing the antibody screen by tube method, the cells must be washed
following incubation at least:
a. Once
b. 3 times
c. 5 times
d. 10 times
13. T F A wash step is not necessary when using the solid phase adherence
method for the antibody screen.
14. T F An excess of serum proteins may cause false positive results in the
immediate spin and 37C phases of the antibody screen.
15. When performing the antibody screen by tube method, you discover the heat
block is set at 35 o C. How would this affect your test?
a. No effect. Incubation in a heat block is not indicated in an indirect
antiglobulin test procedure.
b. No effect. 35 o C is within the proper temperature range for incubation.
c. Must incubate longer to compensate for the decreased temperature.
d. Invalidates test, as temperature is too low for IgG antibodies to react.
16. When performing the antibody screen by gel method, you discover the screen
cells are only in a 0.8% cell suspension. How would this affect your test?
a. Must add 2 additional drops of cells to correct the serum: cell ratio.
b. No effect. 0.8% is the correct cell suspension for the gel method.
c. Wash the screen cells and resuspend with saline to a 2-5% suspension
d. Will need to centrifuge an additional 10 minutes to ensure all screen cells
enter the gel.
CLS 422 Clinical Immunohematology I Page 3 of 6
Student Lab Day Two Take Home Quiz