Chapter 9

A

1. Which of the following statements is true regarding interpretation of SPRCA results?

a. Grading reactions is based on a l-to-4 grading scale where 4+ is a strong positive.

b. A tight button of cells on the bottom of the well would be interpreted as a positive reaction.

c. Hemagglutination assay results are interpreted the same as SPRCA results.

d. An evenly distributed layer of cells on the well surface is a negative reaction.

C

Indicator cells used in SPRCA are:

a. IgM-coated red cells useful in determining the presence of ABO antibodies

b. cells used to agglutinate IgG antibodies to form a pellet in the well after centrifugation

c. IgG-coated red cells that cross-link with IgG antibodies attached to the well

d. check cells that are added to negative reactions to validate the washing step

C

3. In the gel test, a button of cells at the bottom of the well is

a:

a. 4+ positive reaction

c. negative reaction

b. 1+ positive reaction

d. invalid reaction

B

4. The gel test and SPRCA share which of the following advantages over the antiglobulin tube testing method?

a. both use prediluted cells, saving reagent expense

b. endpoints are stable and reviewable for at least 2 days

c. centrifugation is not required for either system

d. a washing step is not required for either system

D

5. Which method is used in the automated Immucor system for ABO and D phenotype?

a. solid phase red cell adherence assay (SPRCA)

b. enzyme-linked immunosorbent assay (ELISA)

c. reverse-passive hemagglutination (RPHA)

d. hemagglutination in a microwell

D

6. False-negative reactions can occur in both gel test and SPRCA for which of the following errors?

a. failing to centrifuge

c. incubation time was too short

b. not mixing reagent red cells sufficiently

d. all of the above

C

7. Mixed-field reactions were observed in the 1D-MTS Gel Test for ABO and D phenotype using the ORTHO Pro Vue. What is the most likely cause of this observation?

a. improper pipetting technique

b. the use of contaminated reagents

c. transfusion of group O cells to an A or B patient

d. centrifugation error

B

8. After centrifugation using the ID-MTS anti-IgG gel cards, a layer of agglutinated cells was observed at the top of two of the three screening cell microtubes. What should be done next?

a. repeat the test

b. proceed to an antibody identification panel

c. perform a DAT to determine if the patient has an autoantibody

d. verify the negative reaction with check cells

A

9. The MTS Monoclonal A/B/D Grouping Gel Card is used for:

a. typing A, B, and D antigen

c. typing Rh system antigens

b. antiglobulin crossmatches

d. direct antiglobulin test

D

10. The Capture-R select microwell strips are used for:

a. direct antiglobulin test

b. antiglobulin testing of selected panel cells

c. weak D test

d. all of the above

A

11. Bar-code technology is used in automated instruments to ensure positive sample identity.

a. True

b. False

A

12. LIS interfaces link the automated test system with a laboratory information system for reporting results.

a. True

b. False

A

13. Automation should make it easier to do things the right way and more difficult to do the wrong things.

a. True

b. False

B

14. When selecting an automation partner , a laboratory does not need to determine its requirements in terms of customer support, training, and service.

a. True

b. False

A

15. Rapid turnaround times for selected samples and the ability to accommodate large volume batch testing contribute to overall operational efficiency.

a. True

b. False

A

16. Vendors of automation for the transfusion service require prior approval from the FDA.

a. True

b. False

A

17. Vendor assessment, base technology, and instrument assessment are important considerations in the selection of an automated system.

a. True

b. False

A

18. Automation can be purchased for gel technology and SPRCAs.

a. True

b. False

B

19. Because of the sensitivity of the SPRCAs and gel assays, the immediate-spin crossmatch for detecting ABO compatibility is no longer necessary.

a. True

b. False