Deck 12: Other Technologies and Automation

Question 1

The indicator cells used to detect antibodies in a solid phase technology are:

A) anti-D coated RBCs.
B) AHG-coated RBCs.
C) plain RBC suspension.
D) antibody screen cell I.

Answer 1

B

Question 2

Low ionic strength saline (LISS) is added to antibody screening methods for which of the following test systems?

A) Gel
B) SPRCA
C) Solid phase
D) None of the above

Answer 2

B

Question 3

In performing an antibody screen by the solid phase technique, a monolayer of red blood cells is formed at the top of the microplate wells following the addition of indicator cells. This result should be interpreted as:

A) negative.
B) mixed-field.
C) positive.
D) weak positive.

Answer 3

C

Question 4

Upon centrifugation of an antibody screen procedure done by the gel system, the red blood cell agglutinates are dispersed throughout the gel column with a few agglutinates at the bottom of the microtubes. This reaction should be graded as a:

A) 4+ reaction.
B) 3+ reaction.
C) 2+ reaction.
D) 1+ reaction.

Question 5

The washing procedure is applicable to which of the following serologic methods?

A) Solid phase and tube system
B) Gel technology and solid phase
C) Solid phase and affinity column
D) Gel technology and tube system

Question 6

In a gel-based technology, the solid band at the top of the gel indicates a_____ , whereas formation of a pellet at the bottom of the microtubes indicates_____ .

A) 4+ reaction/a negative reaction
B) negative reaction/a 4+ reaction
C) 3+ reaction/a negative reaction
D) mixed field reaction/subgroups

Question 7

The FDA has approved the _____ for application of gel technology.

A) ABO, Rh, DAT, antibody screen and identification, as well as crossmatching
B) ABO, antibody screen, and DAT
C) Antibody screen, antibody identification, and crossmatching
D) ABO, Rh, DAT, and antibody screen

Question 8

Which of the following tests is not available for both the gel testing method and solid phase technology?

A) AHG
B) ABO
C) DAT
D) None of the above

Question 9

If you had a lipemic and icteric sample that needed to have an antibody screen done, which of the following would obtain the best results?

A) Tube method
B) Gel
C) Solid phase
D) SPRCA

Question 10

Using the affinity column technique, a serologic reaction that forms a fine red blood cell band at the top of the gel column and a red blood cell button at the bottom of the gel column is interpreted as:

A) mixed-field
B) weak positive
C) strong positive
D) negative

Question 11

The gel system has all of the following advantages over the traditional tube procedure except:

A) standardization in reading technique.
B) stability of the test reaction.
C) replicability of the test results.
D) different grading system.

Question 12

A layer of red blood cells agglutinates at the top of the gel media, and a pellet of unagglutinated red blood cells forms at the bottom. These findings are comparable to which of the following reactions in the test tube?

A) Negative
B) Weak positive
C) Mixed-field
D) Invalid

Question 13

Using the gel test system, the technologist used a 3% cell solution. What would be the probable outcome?

A) Normal
B) Weaker results because of the increase in antigen/antibody ratio
C) Stronger results because of the increase in antigen/antibody ratio
D) None of the above

Question 14

Which of the following is a factor in possible false-negative or false-positive results when using the gel system to screen for antibodies?

A) Bacterial contamination
B) Temperature
C) Time
D) All of the above

Question 15

Which of the following substances may interfere with gel technology but not SPRCA technology?

A) Hemolysis
B) Lipemia
C) Icteric samples
D) All of the above

Question 16

After completing an antibody screen using the gel testing method, results after centrifugation yield a pellet of unagglutinated cells at the bottom of the microtube and a thin layer of cells at the top gel column. This situation commonly indicates:

A) a cold agglutinin.
B) a warm autoantibody.
C) that fibrin from serum that has not clotted completely.
D) a contaminated patient specimen.

Question 17

Which of the following factors are likely to cause false-positive results while using gel technology?

A) Lipemia
B) Icteric sample
C) Rouleaux
D) All of the above

Question 18

When performing an antibody screen by gel technology, the following steps are eliminated:

A) the AHG reagent and control checked cells.
B) the saline wash and control check cells.
C) the cells I and II and saline wash.
D) the centrifugation and saline wash.

Question 19

Which of the following statements is the most accurate? A mixed-field in the gel system:

A) can be ignored without further workup.
B) can be caused by fibrin found in plasma and can be corrected by using fresh serum.
C) needs to have further testing performed.
D) can be resolved by respinning the gel card.

Question 20

An anti-M detected by using gel AHG antibody screening cards is considered clinically insignificant.