Blood Banking Assessment Exam AABB
ASCP Standards Official Practice Exam
Actual Exam 2026/2027 with Detailed
Rationales | Complete Exam-Style
Questions | Pass Guaranteed – A+
Graded
══════════════════════════════════════
SECTION 1: IMMUNOHEMATOLOGY & BLOOD GROUP SYSTEMS Q1 – Q10
══════════════════════════════════════
Question 1 of 50
A 25-year-old pregnant woman is typed during her first prenatal visit. Forward typing shows 4+
agglutination with anti-A and no reaction with anti-B. Reverse typing reveals her plasma
agglutinates B reagent cells 4+ and A1 reagent cells 1+. A2 reagent cells show no
agglutination.
A. She is group A2 with naturally occurring anti-A1 ✓ CORRECT
B. She is group A1 with a cold autoantibody
C. She is group O with an acquired A antigen
D. She is group B with weak B antigen expression
Correct Answer: A
Rationale: Forward typing with anti-A only indicates group A or A subgroup, and the presence
of anti-A1 in the plasma reacting with A1 cells but not A2 cells is characteristic of the A2
phenotype. Group A1 would not produce anti-A1, and group O would not react with anti-A in
forward typing. This pattern is commonly encountered in prenatal testing and requires no
special transfusion precautions beyond standard ABO matching.
Question 2 of 50
A 67-year-old woman with warm autoimmune hemolytic anemia is typed before surgery. Her
red cells show 1+ agglutination in all forward typing reagents including anti-A, anti-B, and
anti-D. The autocontrol is 2+ positive.
,A. Perform an elution to recover antibody from the red cells
B. Wash the cells extensively and test with IgG-sensitive anti-D in albumin ✓ CORRECT
C. Perform a direct antiglobulin test with anti-IgG and anti-C3d
D. Type the patient using a saliva sample for secretor status
Correct Answer: B
Rationale: In warm AIHA, autoantibody coating the red cells can cause weak or false-positive
reactions in forward typing, and extensive washing with warm saline helps remove bound
immunoglobulin to allow accurate Rh typing with potent reagents. Performing an elution
would recover autoantibody but does not help resolve the type, and repeating the DAT is
unnecessary since hemolysis is already established. Saliva testing is not used for Rh
determination and would not address the immediate need for transfusion compatibility.
Question 3 of 50
A 19-year-old college student donates blood for the first time. Forward typing shows no
reaction with anti-A or anti-B. Reverse typing shows 4+ agglutination with both A1 and B
reagent cells. The cell button appears slightly mixed-field during Rh typing with anti-D.
A. Test the donor plasma with a panel of screening cells at 37°C
B. Perform an antibody identification panel using enzyme-treated cells
C. Test with anti-D reagent using a more sensitive technique such as the weak D test ✓
CORRECT
D. Perform a direct antiglobulin test on the donor red cells
Correct Answer: C
Rationale: A mixed-field or weak reaction in Rh typing of a group O donor suggests a weak D
phenotype, which requires testing with a more sensitive anti-D technique such as the indirect
antiglobulin test. Testing the plasma with screening cells or performing an antibody panel
would not address the Rh typing discrepancy, and a direct antiglobulin test detects antibody
coating rather than determining D status. Donors with weak D are typically managed as
D-positive for transfusion purposes.
Question 4 of 50
A 34-year-old woman of African descent is typed before cesarean delivery. Her red cells show
4+ agglutination with anti-A and no reaction with anti-B. Anti-D is 4+ positive. She
demonstrates 3+ agglutination with anti-C and 2+ with anti-E. Her antibody screen is
negative.
A. R1R1 (DCe/DCe)
B. R2R2 (DcE/DcE)
C. R1r (DCe/dce)
D. R1R2 (DCe/DcE) ✓ CORRECT
, Correct Answer: D
Rationale: The R1R2 genotype is the only common genotype that produces both C and E
antigens on the red cells, which is consistent with the typing results. R1R1 is E negative, R2R2
is C negative, and R1r would typically be E negative. This genotype is frequently observed in
individuals of African descent and has no special transfusion implications beyond routine Rh
matching.
Question 5 of 50
A 52-year-old man with a history of gastric bypass surgery presents for preoperative type and
screen. Forward typing shows no reaction with anti-A or anti-B, but reverse typing shows only
weak 1+ agglutination with A1 reagent cells and no reaction with B reagent cells. His
antibody screen is negative.
A. Reduced anti-A and anti-B titers due to low immunoglobulin levels post-surgery ✓
CORRECT
B. Group A2 with weak A antigen expression on red cells
C. Group B with acquired A-like antigen from intestinal bacteria
D. Bombay phenotype with anti-H reacting weakly at room temperature
Correct Answer: A
Rationale: Gastric bypass surgery can lead to malabsorption and reduced immunoglobulin
levels, which may result in weak or absent reverse typing reactions despite a normal forward
type. Group A2 would show weak forward typing with anti-A, and group B would react with
anti-B in forward typing. The Bombay phenotype would show no reaction with anti-A or anti-B
and strong reactions with all reagent cells in reverse typing.
Question 6 of 50
A neonate born to a group O, Rh-negative mother is typed from cord blood. Forward typing
shows weak 1+ agglutination with anti-A and no reaction with anti-B. The direct antiglobulin
test is positive with anti-IgG.
A. The infant is group O with a false-positive DAT from Wharton's jelly contamination
B. The infant is group A with A antigen poorly developed at birth and maternal anti-A coating
the cells ✓ CORRECT
C. The infant is group A with anti-A passively transferred from breast milk
D. The infant is group AB with weak B antigen expression
Correct Answer: B
Rationale: Neonatal red cells have poorly developed A and B antigens, which explains the
weak forward typing, and the positive DAT reflects maternal anti-A coating the infant's cells in
ABO hemolytic disease. Wharton's jelly contamination can cause a false-positive DAT but
does not explain the weak anti-A reaction, and breast milk does not transfer antibodies in
ASCP Standards Official Practice Exam
Actual Exam 2026/2027 with Detailed
Rationales | Complete Exam-Style
Questions | Pass Guaranteed – A+
Graded
══════════════════════════════════════
SECTION 1: IMMUNOHEMATOLOGY & BLOOD GROUP SYSTEMS Q1 – Q10
══════════════════════════════════════
Question 1 of 50
A 25-year-old pregnant woman is typed during her first prenatal visit. Forward typing shows 4+
agglutination with anti-A and no reaction with anti-B. Reverse typing reveals her plasma
agglutinates B reagent cells 4+ and A1 reagent cells 1+. A2 reagent cells show no
agglutination.
A. She is group A2 with naturally occurring anti-A1 ✓ CORRECT
B. She is group A1 with a cold autoantibody
C. She is group O with an acquired A antigen
D. She is group B with weak B antigen expression
Correct Answer: A
Rationale: Forward typing with anti-A only indicates group A or A subgroup, and the presence
of anti-A1 in the plasma reacting with A1 cells but not A2 cells is characteristic of the A2
phenotype. Group A1 would not produce anti-A1, and group O would not react with anti-A in
forward typing. This pattern is commonly encountered in prenatal testing and requires no
special transfusion precautions beyond standard ABO matching.
Question 2 of 50
A 67-year-old woman with warm autoimmune hemolytic anemia is typed before surgery. Her
red cells show 1+ agglutination in all forward typing reagents including anti-A, anti-B, and
anti-D. The autocontrol is 2+ positive.
,A. Perform an elution to recover antibody from the red cells
B. Wash the cells extensively and test with IgG-sensitive anti-D in albumin ✓ CORRECT
C. Perform a direct antiglobulin test with anti-IgG and anti-C3d
D. Type the patient using a saliva sample for secretor status
Correct Answer: B
Rationale: In warm AIHA, autoantibody coating the red cells can cause weak or false-positive
reactions in forward typing, and extensive washing with warm saline helps remove bound
immunoglobulin to allow accurate Rh typing with potent reagents. Performing an elution
would recover autoantibody but does not help resolve the type, and repeating the DAT is
unnecessary since hemolysis is already established. Saliva testing is not used for Rh
determination and would not address the immediate need for transfusion compatibility.
Question 3 of 50
A 19-year-old college student donates blood for the first time. Forward typing shows no
reaction with anti-A or anti-B. Reverse typing shows 4+ agglutination with both A1 and B
reagent cells. The cell button appears slightly mixed-field during Rh typing with anti-D.
A. Test the donor plasma with a panel of screening cells at 37°C
B. Perform an antibody identification panel using enzyme-treated cells
C. Test with anti-D reagent using a more sensitive technique such as the weak D test ✓
CORRECT
D. Perform a direct antiglobulin test on the donor red cells
Correct Answer: C
Rationale: A mixed-field or weak reaction in Rh typing of a group O donor suggests a weak D
phenotype, which requires testing with a more sensitive anti-D technique such as the indirect
antiglobulin test. Testing the plasma with screening cells or performing an antibody panel
would not address the Rh typing discrepancy, and a direct antiglobulin test detects antibody
coating rather than determining D status. Donors with weak D are typically managed as
D-positive for transfusion purposes.
Question 4 of 50
A 34-year-old woman of African descent is typed before cesarean delivery. Her red cells show
4+ agglutination with anti-A and no reaction with anti-B. Anti-D is 4+ positive. She
demonstrates 3+ agglutination with anti-C and 2+ with anti-E. Her antibody screen is
negative.
A. R1R1 (DCe/DCe)
B. R2R2 (DcE/DcE)
C. R1r (DCe/dce)
D. R1R2 (DCe/DcE) ✓ CORRECT
, Correct Answer: D
Rationale: The R1R2 genotype is the only common genotype that produces both C and E
antigens on the red cells, which is consistent with the typing results. R1R1 is E negative, R2R2
is C negative, and R1r would typically be E negative. This genotype is frequently observed in
individuals of African descent and has no special transfusion implications beyond routine Rh
matching.
Question 5 of 50
A 52-year-old man with a history of gastric bypass surgery presents for preoperative type and
screen. Forward typing shows no reaction with anti-A or anti-B, but reverse typing shows only
weak 1+ agglutination with A1 reagent cells and no reaction with B reagent cells. His
antibody screen is negative.
A. Reduced anti-A and anti-B titers due to low immunoglobulin levels post-surgery ✓
CORRECT
B. Group A2 with weak A antigen expression on red cells
C. Group B with acquired A-like antigen from intestinal bacteria
D. Bombay phenotype with anti-H reacting weakly at room temperature
Correct Answer: A
Rationale: Gastric bypass surgery can lead to malabsorption and reduced immunoglobulin
levels, which may result in weak or absent reverse typing reactions despite a normal forward
type. Group A2 would show weak forward typing with anti-A, and group B would react with
anti-B in forward typing. The Bombay phenotype would show no reaction with anti-A or anti-B
and strong reactions with all reagent cells in reverse typing.
Question 6 of 50
A neonate born to a group O, Rh-negative mother is typed from cord blood. Forward typing
shows weak 1+ agglutination with anti-A and no reaction with anti-B. The direct antiglobulin
test is positive with anti-IgG.
A. The infant is group O with a false-positive DAT from Wharton's jelly contamination
B. The infant is group A with A antigen poorly developed at birth and maternal anti-A coating
the cells ✓ CORRECT
C. The infant is group A with anti-A passively transferred from breast milk
D. The infant is group AB with weak B antigen expression
Correct Answer: B
Rationale: Neonatal red cells have poorly developed A and B antigens, which explains the
weak forward typing, and the positive DAT reflects maternal anti-A coating the infant's cells in
ABO hemolytic disease. Wharton's jelly contamination can cause a false-positive DAT but
does not explain the weak anti-A reaction, and breast milk does not transfer antibodies in
