Blood Bank Ch 3: Blood Banking Reagents Overview and Applications
Which of the following is NOT an advantage of using a monoclonal antibody over a polyclonal antibody? - There are very few variations between lots. - There are no contaminating antibodies. - Direct agglutination is usually faster. - All variations of the antigen can be detected
All variations of the antigen can be detected
Reagent to identify the specificity of a red cell antibody
Panel cells
Following centrifugation of the gel card, red cells are evenly dispersed throughout one of the microtubes. This reaction could be graded as a:
2+
What temperature is used for incubation in the indirect antihuman globulin test? - 22° C - 37° C - 4° C - 56° C
37° C
In the solid-phase red cell adherence test, how does a negative test appear? - A button of cells on the bottom of the well - Adherence of cells along the sides and bottom of the wells - Hemolysis of red cells - A line of cells along the top of the well
A button of cells on the bottom of the well
Reagent used in the identification of ABO antibodies
A1 and B cells
Reagent used to determine the ABO antigenic composition of a patient's red cells
ABO antisera
Which of the following items provides evidence for reagent red cell deterioration? - Spontaneous agglutination - Significant hemolysis - Loss of agglutination strength over time - All of the above
All of the above
Which of the following statements is true regarding high-protein anti-D reagents? - They have been largely replaced with low-protein monoclonal reagents. - They contain approximately 20% bovine albumin. - They may increase the possibility of a false-positive reaction, requiring the use of a control. - All of the above are true.
All of the above are true
What specificities does polyspecific antihuman globulin contain? - Anti-IgG. - Anti-C3b and anti-C3d. - Anti-IgG and anti-C3d. - Anti-IgG and anti-IgM.
Anti-IgG and anti-C3d
Which of the following red cell antigens do proteolytic enzymes destroy? - Rh system antigens - Antigens Fya and Fyb in the Duffy system - Antigens in the Kidd system - Lewis system antigens
Antigens Fya and Fyb in the Duffy system
Select the test that uses IgG-sensitized red cells (check cells). - Antiglobulin test - D-antigen typing - Rh-antigen typing - B-antigen detection
Antiglobulin test
Antiglobulin test(s) that detects IgG or complement-coated red cells
Both the direct and indirect antiglobulin test
Antiglobulin test(s) that requires washing the cells several times before the addition of antihuman globulin reagent
Both the direct and indirect antiglobulin test
What is the purpose of adding antibody-sensitized red cells following the antiglobulin test?
Check that the wash procedure was sufficient to remove unbound antibodies
Antiglobulin test(s) that tests for certain clinical conditions such as hemolytic disease of the newborn and autoimmune hemolytic anemia
Direct antiglobulin test
antiglobulin test(s) in which incubation step is not necessary
Direct antiglobulin test
Select the method that uses a dextran-acrylamide matrix. - Solid-phase red cell adherence - Microplate - Gel technology - Tube techniques
Gel technology
What immunoglobulin class reacts best by antiglobulin testing?
IgG
Why is polyethylene glycol reagent added to the screen or panel?
Increase the avidity of IgG antibodies
Reagent derived from plants used to distinguish group A1 from group A2 red cells
Lectins
What reagent contains antibodies to multiple antigenic epitopes?
Polyclonal-based
Which red cells are used to screen for antibodies in donor samples? - Screening cells (two vials) - Pooled screening cells - Panel cells - Screening cells (three vials)
Pooled screening cells
Where are product limitations and technical considerations for each reagent located?
Product insert
Reagent to detect the presence of red cell antibodies
Screening cells
Why is incubation omitted in the direct antihuman globulin test?
The antigen-antibody complex has already formed in vivo
The antiglobulin test was performed using gel technology. A button of cells was observed at the bottom of the microtube following centrifugation. How do you interpret this result? - There is a problem with the card. - The result is a negative reaction. - The result is a strong positive reaction. - The test was not washed correctly.
The result is a negative reaction
Which of the following statements is true regarding IgG-sensitized red cells? - They must be used to confirm a negative antiglobulin tube test. - They must be used to confirm a positive antiglobulin test. - They must be used to confirm a direct antiglobulin test that was negative with anti-C3d. - They should be used only with the indirect antiglobulin test.
They must be used to confirm a negative antiglobulin tube test
How would you interpret the results if both the anti-D reagent and the Rh control were 2+ agglutination reactions?
Unable to determine without further testing
Rouleaux is a false-positive reaction that would not likely be observed during which of the following tests? - Immediate-spin antibody screen - Weak D test - Reverse typing in the ABO test - ABO forward typing
Weak D test
The gel technology method uses a concentration of red cells that is:
lower than tube techniques (gel method uses 0.8% suspension of red cells)
Reagent antibodies prepared from human sources are: - unsafe. - too low in potency to be effective. - polyclonal in specificity. - preferred because of their lower cost
polyclonal in specificity
Solid-phase red cell adherence used for antibody detection has an advantage over tube testing because:
the endpoint is more clearly defined
Monoclonal antibodies are prepared in:
vitro