Question 1

In transfusion medicine,the antihuman globulin (AHG)technique is used for numerous purposes including&#10;A)Analyzing DNA&#10;B)Detecting unexpected antibodies&#10;C)Diagnosing the presence of human globulin&#10;D)Inspecting microorganisms

Accepted Answer

The antihuman globulin (AHG) technique is primarily used to detect unexpected antibodies in the patient's blood sample, especially in cases of blood transfusions or pregnancy complications. AHG reagent is added to the mixture of patient serum and red blood cells, and if any antibodies are present, they will bind to the red cells forming immune complexes. This test helps to prevent hemolytic transfusion reactions or hemolytic disease of the newborn. AHG technique is not used for analyzing DNA or inspecting microorganisms, and it does not diagnose the presence of human globulin.

Question 2

All of the following can cause false results in both an indirect (IAT)or direct (DAT)antiglobulin test except&#10;A)Contaminated saline&#10;B)Inadequate incubation&#10;C)Interruption in testing&#10;D)Improper centrifugation

Accepted Answer

Inadequate incubation

Question 3

Which of the following would be a disadvantage to using a monoclonal reagent?&#10;A)No contaminating antibodies&#10;B)Small variation between batches&#10;C)Specificity may be relative&#10;D)Unlimited production

Accepted Answer

Monoclonal reagents can have relative specificity, meaning they may not bind to all possible epitopes of a target molecule. This can result in false negatives or incomplete detection. The other options listed are advantages of using monoclonal reagents, including no contaminating antibodies, small variation between batches, and unlimited production.

Question 4

For tube testing,the most commonly used plasma-to-cell ratio is&#10;A)One drop of plasma and one drop of 5% suspension of red blood cells&#10;B)One drop of plasma and two drops 5% suspension of red blood cells&#10;C)Two drops of plasma and one drop of 5% suspension of red blood cells&#10;D)Two drops of plasma and two drops of 5% suspension of red blood cells

Accepted Answer

The most commonly used plasma-to-cell ratio for tube testing is two drops of plasma to one drop of a 5% suspension of red blood cells. This ratio ensures optimal conditions for agglutination reactions.

Question 5

Which of the following tests does not detect antibodies to red blood cell antigens?&#10;A)Antibody screen&#10;B)Antibody identification&#10;C)Antigen typing&#10;D)Crossmatch

Accepted Answer

Antigen typing detects the presence or absence of red blood cell antigens, while antibody screen, antibody identification, and crossmatch all detect antibodies to red blood cell antigens.

Question 6

During the AHG phase of an antibody screen test,before adding AHG reagent to the test tubes,what should the red blood cells be washed with?&#10;A)Distilled water&#10;B)Iodine&#10;C)Saline&#10;D)Soap

Accepted Answer

Before adding AHG reagent to the test tubes, the red blood cells should be washed with saline. This is because saline is an isotonic solution and will help to remove any unbound antibodies or proteins that could interfere with the test results. Distilled water, iodine, and soap are not appropriate for washing red blood cells in this context.

Question 7

All of the following statements are true regarding the indirect antiglobulin test (IAT)except&#10;A)Begins with a source of antigen and antibody being added to the test system&#10;B)Consists of a two-step method&#10;C)Has a first step where anti-IgG attaches to any IgG coating the red blood cells&#10;D)Is a very versatile test within the blood bank laboratory

Accepted Answer

The first step of the IAT involves incubating red blood cells with serum to allow antibodies to bind to antigens on the cells, not the attachment of anti-IgG.

Question 8

Antihuman globulin (AHG)reagent must contain anti-_____ when used for antibody detection.&#10;A)C3d&#10;B)IgA&#10;C)IgG&#10;D)IgM

Accepted Answer

Antihuman globulin (AHG) reagent is used to detect antibodies, and the AHG reagent must contain antibodies against the immunoglobulin class that is being tested for. In most cases, the AHG reagent will contain antibodies against IgG, which is the most common immunoglobulin involved in transfusion reactions, hemolytic disease of the newborn, and other immune-mediated transfusion reactions. While AHG reagents may also contain antibodies against other immunoglobulins (such as IgM or IgA), the best choice for this question is C) IgG, as it is the most commonly targeted immunoglobulin in AHG reagents.

Question 9

Which of the following does not activate complement?&#10;A)IgG1&#10;B)IgG2&#10;C)IgG3&#10;D)IgG4

Accepted Answer

IgG4 does not activate complement. While IgG1, IgG2, and IgG3 all have the ability to activate complement through the classical pathway, IgG4 has a hinge region that prevents complement binding.

Question 10

Antibody screen tests must include an incubation step at what temperature,which is the optimal reaction temperature for IgG antibodies?&#10;A)39.2&#176; F (4&#176; C)&#10;B)71.6&#176; F (22&#176; C)&#10;C)91.4&#176; F (33&#176; C)&#10;D)98.6&#176; F (37&#176; C)

Accepted Answer

The optimal reaction temperature for IgG antibodies is at 98.6° F (37° C), which is the same as body temperature. Therefore, the incubation step should be performed at this temperature for accurate antibody screening.

Question 11

The antihuman globulin technique is used to detect which isotype of antibody?&#10;A)IgD&#10;B)IgE&#10;C)IgG&#10;D)IgM

Accepted Answer

The answer of The antihuman globulin technique is used to...

Question 12

The primary purpose of the immediate spin phase is to detect antibodies that react at room temperature,typically antibodies of the _____ class.&#10;A)IgA&#10;B)IgE&#10;C)IgG&#10;D)IgM

Accepted Answer

The answer of The primary purpose of the immediate spin...

Question 13

_________ is typically added before the incubation phase of the antibody screen test.&#10;A)AHG&#10;B)DAT&#10;C)IgG&#10;D)PEG

Accepted Answer

The answer of _________ is typically added before the incubation...

Question 14

When the body first encounters a foreign antigen,a primary immune response is stimulated.One of the residual effects of the primary response is the retention of which memory cells?&#10;A)B&#10;B)D&#10;C)X&#10;D)Y

Accepted Answer

The answer of When the body first encounters a foreign...

Question 15

When grading agglutination in a gel microtubule system,which grade is described as cells and agglutinates distributed through the column?&#10;A)1+&#10;B)2+&#10;C)3+&#10;D)4+

Accepted Answer

The answer of When grading agglutination in a gel microtubule...

Question 16

The most common cause for the check cells not reacting is&#10;A)Incorrect use of tubes&#10;B)Improper washing&#10;C)Malfunctioning equipment&#10;D)Too much time in the centrifuge

Accepted Answer

The answer of The most common cause for the check...

Question 17

All of the following are characteristics of IgG except&#10;A)Demonstrates agglutination in antiglobulin tests&#10;B)Has a plasma half-life of about 23 days&#10;C)Has a valence of 10&#10;D)Is able to cross the placenta

Accepted Answer

The answer of All of the following are characteristics of...

Question 18

All of the following are true regarding the direct antiglobulin test (DAT)except&#10;A)Detects sensitization in vivo of red blood cells with antibody or complement&#10;B)Is performed in order to visualize antigen-antibody reactions that happened in the body,not the test tube&#10;C)Is usually included in routine pretransfusion testing&#10;D)Omits the incubation at 98.6&#176; F (37&#176; C)phase

Accepted Answer

The answer of All of the following are true regarding...

Question 19

During the incubation phase of an antibody screen test,how long should the test tubes be incubated?&#10;A)5-10 minutes&#10;B)10-30 minutes&#10;C)Depends on the temperature of incubation&#10;D)Depends on the enhancement reagent added

Accepted Answer

The answer of During the incubation phase of an antibody...

Question 20

______ is the first immunoglobulin class produced in a primary immune response.&#10;A)IgD&#10;B)IgE&#10;C)IgG&#10;D)IgM

Accepted Answer

The answer of ______ is the first immunoglobulin class produced...

Deck 3: Blood Bank Applications of Antigenantibody Reactions