Question 1

When carrier particles are coated with an antigen that is not normally found on them,this is known as:&#10;A) direct agglutination&#10;B) passive agglutination&#10;C) reverse passive agglutination&#10;D) hemagglutination

Accepted Answer

Passive agglutination refers to the process where carrier particles (such as latex beads) are coated with antigens not normally present on their surface, to detect antibodies against such antigens in a patient's serum.

Question 2

Which antibody class may require the use of an enhancement technique to visualize the reaction?&#10;A) IgM&#10;B) IgG&#10;C) IgA&#10;D) IgE

Accepted Answer

IgG antibodies are often present in lower concentrations and may not precipitate as visibly in certain assays, requiring enhancement techniques for detection.

Question 3

What would be the best test to determine evidence of hemolytic disease of the newborn?&#10;A) direct antiglobulin testing&#10;B) passive agglutination&#10;C) coagglutination testing&#10;D) indirect antiglobulin testing

Accepted Answer

indirect antiglobulin testing

Question 4

A serological reaction is set up in which the antigen is bound to a large carrier,the antibody is soluble,and they bind and form an insoluble complex that is detected macroscopically.What type of assay is described?

A) precipitation
B) agglutination
C) flocculation
D) neutralization

Accepted Answer

The answer of A serological reaction is set up in...

Question 5

Coombs' reagent is used for what purpose?&#10;A) to link small antigens on patient red cells&#10;B) to enhance agglutination with IgG coated red blood cells&#10;C) to enhance agglutination with IgM coated red blood cells&#10;D) to cause a precipitation reaction with small amounts of antibody

Accepted Answer

Coombs' reagent, also known as anti-human globulin (AHG), is used to enhance agglutination with IgG coated red blood cells. It is used in blood typing, cross-matching, and in detecting antibodies that are directed against red blood cells.

Question 6

Which of the following would enhance an agglutination reaction?&#10;A) polyethylene glycol (PEG)&#10;B) high ionic strength saline&#10;C) running the reaction at 4C&#10;D) running the reaction at a high pH

Accepted Answer

Polyethylene glycol (PEG) can enhance antibody-antigen agglutination reactions by promoting the formation of larger agglutination complexes. This occurs by PEG causing dehydration of the particles, which results in the particles being more closely packed together, promoting agglutination. High ionic strength saline can also enhance agglutination reactions to some extent but not as effectively as PEG. Running the reaction at 4C or a high pH can impair agglutination reactions as the antibody-antigen complex may dissociate at these extreme temperatures or pH values.

Question 7

If a Coombs' test is positive,which of the following is true?&#10;A) Antibody has coated patient red blood cells in vitro.&#10;B) Antigen is reacting with patient antibody.&#10;C) Antibody has coated patient red blood cells in vivo.&#10;D) Antigen has coated patient red blood cells in vivo.

Accepted Answer

A positive Coombs' test indicates that antibodies have coated the patient's red blood cells in vivo, causing agglutination (clumping) of the cells. This can lead to destruction of the red blood cells and cause hemolytic anemia.

Question 8

The process by which particulate antigens such as cells aggregate to form larger complexes when specific antibody is present is called:&#10;A) sensitization&#10;B) precipitation&#10;C) agglutination&#10;D) flocculation

Accepted Answer

Agglutination is the process of particulate antigens clumping together when specific antibodies are present. Precipitation involves the same process, but with soluble antigens instead of particulate antigens. Sensitization refers to the initial step in the immune response where an antigen is recognized and bound by an antibody or a T-cell receptor. Flocculation is a similar process to precipitation, but involves the clumping together of fine, suspended particles in a liquid rather than antigens.

Question 9

When a patient's red blood cells combine with anti-A typing serum to produce a positive result,this reaction is known as:&#10;A) passive agglutination&#10;B) reverse passive agglutination&#10;C) hemagglutination&#10;D) flocculation

Accepted Answer

Hemagglutination is the process by which red blood cells clump together in response to the presence of an antibody. In the case of anti-A typing serum, if it reacts with the A antigen on a patient's red blood cells, it will cause hemagglutination and produce a positive result. Passive agglutination and reverse passive agglutination are similar processes, but they refer to reactions that occur in the presence of different types of antigens or antibodies. Flocculation is a more general term that refers to the clumping of particles in a solution, and is not specific to red blood cells or immunity.

Question 10

A serological test that uses red blood cells coated with exogenous antigens such as bacterial polysaccharides as a method to detect patient antibodies against that exogenous antigen is called:&#10;A) latex agglutination&#10;B) hemagglutination&#10;C) neutralization&#10;D) complement fixation

Accepted Answer

The serological test that uses red blood cells coated with exogenous antigens such as bacterial polysaccharides as a method to detect patient antibodies against that exogenous antigen is called hemagglutination. During the test, if the patient's serum contains antibodies against the exogenous antigen present on the red blood cells, it will cause agglutination or clumping of the cells. This test is commonly used for the diagnosis of bacterial infections, including Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis.

Question 11

In performing blood typing using the tube method,if the red cell button is not resuspended properly,what are the most likely results?&#10;A) false-positive&#10;B) false-negative&#10;C) doesn't affect the results&#10;D) makes the reaction weaker

Accepted Answer

The answer of In performing blood typing using the tube...

Deck 9: Agglutination