Blood Bank Chapters 2 and 3
which of the following components in the complement cascade mediates the lysis of the target cells?
C5 to C9
found in mucosal linings
IgA
can initiate allergic reactions
IgE
able to cross the placenta
IgG
highest plasma serum concentration
IgG
which immunoglobulin class is impacted by the zeta potential in a hemagglutination test?
IgG
detected with the antiglobulin test
IgG!
contains 10 antigen binding sites
IgM
shape is a pentamer
IgM!
associated with intravascular cell destruction
IgM#
detected in the immediate spin phase of the agglutination test
IgM$
reacts best at room temperature
IgM%
produced early in a immune response
IgM*
activates the complement cascade most efficiently
IgM@
how does complement activation demonstrate within the body?
all of the above
Which of the following is not an advantage of using a monoclonal antibody over a polyclonal antibody?
all of the variations of the antigen can be detected
to determine the presence of a red cell antibody in a patients sample, what is the source of antigen?
commercial reagent red cells
hemolysis was observed at room temperature when testing a patients serum with reagent red cells used for screening. when this test was repeated using the patients plasma, no hemolysis was observed. what was the most likely explanation for the different reactions?
complement activation was inhibited by calcium in the plasma sample
select the term that describes the unique part of the antigen that is recognized by a corresponding antibody.
epitope
a technologist added 4 drops of a 5% red cell suspension instead of the required 1 drop to a hemagglutination test. what is the potential consequence to the results?
false negative
what is the potential effect in a tube agglutination test if a red cell suspension with a concentration greater than 5% is used?
false negatives
what is the chemical composition of an antibody?
glycoprotein
what part of the immunoglobulin molecule distinguishes the isotype?
heavy chain
rouleaux is a false positive reaction caused by elevated serum protein levels?
immediate spin antibody screen
why is polyethylene glycol reagent added to the screen or panel?
increase the avidity of IgG antibodies
which of the following requires adjustment in order to enhance the reaction of an antibody in vitro?
increase the incubation time in the incubator
which of the following situations can enhance hemoagglutination reactions?
increasing the incubation time
what classification of molecules does not make a good immunogenic substance?
lipid
where is the antigen located in a hemoagglutination test?
on the red cell membrane
what term describes molecules that bind to an antigen to increase phagocytosis?
opsonins
after addition of anti a reagent to a patients red cell suspension, agglutination was observed. the result with anti b reagent was negative. what is the interpretation of this patients ABO typing?
patient is group A
what cells can produce antibodies?
plasma cells
which red cells are used to screen for antibodies in donor samples?
pooled screening cells
after performing a tube test, the supernatant of the test was pinkish and the red cell button was small. how do you interpret the results of this test?
positive
what biological molecules are considered the most immunogenic?
proteins
extravascular destruction of blood cells occurs in the:
spleen
solid phase red cell adherence used for antibody detection has an advantage over tube testing because:
the end point is more clearly defined
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?
the result is a negative reaction
which of the following statements is true regarding high protein anti D reagents?
they have been largely replaced with low protein monoclonal reagents
which of the following statements is true regarding IgG sensitized red cells?
they must be used to confirm a negative antiglobuin 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
what term describes the number of antigen binding sites per ,molecule of antibody?
valency
how would you grade an agglutination reaction if you observe many small agglutinants in a background of free cells in tube testing?
1+
following centrifugation of the gel card, red cells are evenly dispersed throughout one of the microtubes. this reaction could be graded as a:
2+
after adding antigen and antibody to a test tube, one large agglutinate was observed. How should this reaction be graded?
4+