MLS UAMS Blood bank Case study
Test 2 Questions and All Correct
Answers 2025-2026.
What is Poly-specific AHG - Answer Antibody to IgG and complement
What is Mono-specific AHG? - Answer Antibody only to IgG or complement only
What are the conditions for which the DAT is most often performed? - Answer 1. Hemolytic
disease of the newborn
2. Drug reactions
3. Autoimmune hemolytic anemia
4. Transfusion reaction
What can be deduced from a negative IAT? - Answer 1. Antibody is present but is too weak
to react
2. Antigen to the corresponding antibody is not present on the screen cells
3. No antibody present in the patients serum
List the criteria which must be met before it is acceptable to perform only an IS crossmatch? -
Answer 1. Negative IAT
2. No previous history of an antibody
3. No typing discrepancies or any other serological inconsistencies
Which of the following must be rejected as the sample for ABO/Rh typing and pretransfusion
testing
A. red top clotted tube
B. EDTA tube
C. Red top tube with added thrombin
D. SST (Serum separator) tube with gel - Answer SST (Serum separator) tube with gel
You are using commercial antisera to antigen type units, and need a panel cell to use as a
positive control. Do you want a cell which is homozygous or heterozygous for the antigen in
question? Why? - Answer It is better to use heterozygous one for the antigen to make sure
the antisera will detect a weak antigen
, Why is it necessary to identify an antibody if compatible blood is found via the crossmatch? -
Answer The antibody must be identified so the units (even if crossedmatch is negative) can
be phenotyped and found lacking the antigen
What is the most common reason that ABO incompatible blood is transfused to someone? -
Answer Clerical or Patient ID error
True or false: Although the crossmatch is the most reliable pre-transfusion test, it does not
detect Rh typing errors, all clerical errors, or extremely low titer antibodies. - Answer True
True or false: If all crossmatch tubes are agglutinated, the units are considered compatible and
units can be transfused to the patient. - Answer Fase, all the tubes must NOT agglutinate for
them to be compatible
True or fasle: A hemolyzed specimen is acceptable for crossmatching. - Answer False,
hemolysis is a sign of a reaction and is considered incompatible, so a hemolyzed sample would
give a false positive
True or false: All Panel cells are group O negative cells - Answer False, some of them are O+
True or False: If the auto control is positive in the antiglobulin phase of the antibody test, a DAT
should be performed - Answer True
True or False: In the indirect antiglobulin tests (IAT), serum contains the antigen. - Answer
False, serum contains the antibody. Red cells contain the antigen.
True or False: Inadequate washing of red cells in the IAT will leave patient's plasma containing
protein around the red cells resulting in neutralization of the AHG - Answer True
True or false: Increasing the volume of serum incubated with a standard volume of red cells may
enhance the reactivity of antibody present in low concentration. - Answer True
True or false: Auto-absorption procedures should not be performed on patients who have been
transfused within the past 3 months. - Answer True
What antibody is associated with Mycoplasma pneumoniae - Answer Anti-I
What antibody is associated with Infectious Mononucleosis - Answer Anti-i
Test 2 Questions and All Correct
Answers 2025-2026.
What is Poly-specific AHG - Answer Antibody to IgG and complement
What is Mono-specific AHG? - Answer Antibody only to IgG or complement only
What are the conditions for which the DAT is most often performed? - Answer 1. Hemolytic
disease of the newborn
2. Drug reactions
3. Autoimmune hemolytic anemia
4. Transfusion reaction
What can be deduced from a negative IAT? - Answer 1. Antibody is present but is too weak
to react
2. Antigen to the corresponding antibody is not present on the screen cells
3. No antibody present in the patients serum
List the criteria which must be met before it is acceptable to perform only an IS crossmatch? -
Answer 1. Negative IAT
2. No previous history of an antibody
3. No typing discrepancies or any other serological inconsistencies
Which of the following must be rejected as the sample for ABO/Rh typing and pretransfusion
testing
A. red top clotted tube
B. EDTA tube
C. Red top tube with added thrombin
D. SST (Serum separator) tube with gel - Answer SST (Serum separator) tube with gel
You are using commercial antisera to antigen type units, and need a panel cell to use as a
positive control. Do you want a cell which is homozygous or heterozygous for the antigen in
question? Why? - Answer It is better to use heterozygous one for the antigen to make sure
the antisera will detect a weak antigen
, Why is it necessary to identify an antibody if compatible blood is found via the crossmatch? -
Answer The antibody must be identified so the units (even if crossedmatch is negative) can
be phenotyped and found lacking the antigen
What is the most common reason that ABO incompatible blood is transfused to someone? -
Answer Clerical or Patient ID error
True or false: Although the crossmatch is the most reliable pre-transfusion test, it does not
detect Rh typing errors, all clerical errors, or extremely low titer antibodies. - Answer True
True or false: If all crossmatch tubes are agglutinated, the units are considered compatible and
units can be transfused to the patient. - Answer Fase, all the tubes must NOT agglutinate for
them to be compatible
True or fasle: A hemolyzed specimen is acceptable for crossmatching. - Answer False,
hemolysis is a sign of a reaction and is considered incompatible, so a hemolyzed sample would
give a false positive
True or false: All Panel cells are group O negative cells - Answer False, some of them are O+
True or False: If the auto control is positive in the antiglobulin phase of the antibody test, a DAT
should be performed - Answer True
True or False: In the indirect antiglobulin tests (IAT), serum contains the antigen. - Answer
False, serum contains the antibody. Red cells contain the antigen.
True or False: Inadequate washing of red cells in the IAT will leave patient's plasma containing
protein around the red cells resulting in neutralization of the AHG - Answer True
True or false: Increasing the volume of serum incubated with a standard volume of red cells may
enhance the reactivity of antibody present in low concentration. - Answer True
True or false: Auto-absorption procedures should not be performed on patients who have been
transfused within the past 3 months. - Answer True
What antibody is associated with Mycoplasma pneumoniae - Answer Anti-I
What antibody is associated with Infectious Mononucleosis - Answer Anti-i
