ASCP MLT EXAM NEWEST 2025/ 2026
ACTUAL EXAM | MEDICAL LABORATORY
TECHNICIAN EXAM PREP WITH
COMPLETE 220 REAL EXAM QUESTIONS
AND CORRECT DETAILED ANSWERS
(VERIFIED ANSWERS) ALREADY GRADED
A+ (MOST RECENT!!)
Section 1: Blood Banking (15-20% of exam)
1. The _____________ effect is the phenomenon of stronger antigen expression with
homozygous genotypes than heterozygous genotypes.
• Answer: dosage
• Rationale: The dosage effect occurs when an antigen reacts more strongly when
there are two copies of a gene (homozygous) than when there is only one copy
(heterozygous) .
2. At which temperature do warm antibodies react with red blood cells?
• Answer: 37°C
• Rationale: Warm antibodies are only active at body temperature (37°C). Cold
antibodies react at lower temperatures .
3. Which type of immunoglobulin is the Donath-Landsteiner antibody?
• Answer: IgG
, • Rationale: The Donath-Landsteiner antibody is an IgG autoantibody that causes
paroxysmal cold hemoglobinuria. It binds to red blood cells in cold temperatures,
leading to hemolysis when the blood warms to 37°C .
4. The most immunogenic blood group antigen is:
• Answer: D (Rh)
• Rationale: The D antigen of the Rh system is the most immunogenic and is the
primary cause of hemolytic disease of the newborn and transfusion reactions.
5. A patient with blood type A has which antibodies in their serum?
• Answer: Anti-B
• Rationale: Individuals with blood type A produce anti-B antibodies in their
serum. Those with type B produce anti-A, type O produce both, and type AB
produce neither.
6. The universal donor for red blood cells is:
• Answer: O negative
• Rationale: O negative red blood cells lack A, B, and Rh antigens, making them
compatible with all blood types.
7. A patient with blood type AB can receive packed red blood cells from which
donors?
• Answer: A, B, AB, O (any ABO type)
• Rationale: Individuals with type AB blood have no ABO antibodies and can
receive red blood cells from any ABO type.
8. Which test is used to detect the presence of Rh antibodies in a pregnant
woman?
• Answer: Indirect antiglobulin test (IAT)
, • Rationale: The IAT detects antibodies in the mother's serum that may cross the
placenta and cause hemolytic disease of the newborn.
9. What is the most likely cause of a transfusion reaction with fever, chills, and
hemoglobinuria?
• Answer: Acute hemolytic transfusion reaction
• Rationale: An acute hemolytic reaction occurs when the recipient's antibodies
destroy transfused RBCs, typically from ABO incompatibility.
10. In blood banking, quality control for blood products includes testing for
bacterial contamination, ensuring proper storage temperature, and:
• Answer: verifying ABO/Rh typing
• Rationale: Blood banking quality control includes donor screening, component
processing verification, storage monitoring, and product testing.
11. Which of the following is a component of the blood banking quality control
process for blood products?
• Answer: Testing for bacterial contamination, ensuring proper storage
temperature, and verifying ABO/Rh typing
• Rationale: Blood banking quality control includes donor screening, component
processing verification, storage monitoring, and product testing.
12. What is the purpose of the direct antiglobulin test (DAT)?
• Answer: To detect antibodies or complement proteins bound to red blood cells
• Rationale: The DAT is used to diagnose hemolytic disease of the newborn and
autoimmune hemolytic anemia.
13. Which blood group system is most important in transfusion medicine?
• Answer: ABO and Rh
ACTUAL EXAM | MEDICAL LABORATORY
TECHNICIAN EXAM PREP WITH
COMPLETE 220 REAL EXAM QUESTIONS
AND CORRECT DETAILED ANSWERS
(VERIFIED ANSWERS) ALREADY GRADED
A+ (MOST RECENT!!)
Section 1: Blood Banking (15-20% of exam)
1. The _____________ effect is the phenomenon of stronger antigen expression with
homozygous genotypes than heterozygous genotypes.
• Answer: dosage
• Rationale: The dosage effect occurs when an antigen reacts more strongly when
there are two copies of a gene (homozygous) than when there is only one copy
(heterozygous) .
2. At which temperature do warm antibodies react with red blood cells?
• Answer: 37°C
• Rationale: Warm antibodies are only active at body temperature (37°C). Cold
antibodies react at lower temperatures .
3. Which type of immunoglobulin is the Donath-Landsteiner antibody?
• Answer: IgG
, • Rationale: The Donath-Landsteiner antibody is an IgG autoantibody that causes
paroxysmal cold hemoglobinuria. It binds to red blood cells in cold temperatures,
leading to hemolysis when the blood warms to 37°C .
4. The most immunogenic blood group antigen is:
• Answer: D (Rh)
• Rationale: The D antigen of the Rh system is the most immunogenic and is the
primary cause of hemolytic disease of the newborn and transfusion reactions.
5. A patient with blood type A has which antibodies in their serum?
• Answer: Anti-B
• Rationale: Individuals with blood type A produce anti-B antibodies in their
serum. Those with type B produce anti-A, type O produce both, and type AB
produce neither.
6. The universal donor for red blood cells is:
• Answer: O negative
• Rationale: O negative red blood cells lack A, B, and Rh antigens, making them
compatible with all blood types.
7. A patient with blood type AB can receive packed red blood cells from which
donors?
• Answer: A, B, AB, O (any ABO type)
• Rationale: Individuals with type AB blood have no ABO antibodies and can
receive red blood cells from any ABO type.
8. Which test is used to detect the presence of Rh antibodies in a pregnant
woman?
• Answer: Indirect antiglobulin test (IAT)
, • Rationale: The IAT detects antibodies in the mother's serum that may cross the
placenta and cause hemolytic disease of the newborn.
9. What is the most likely cause of a transfusion reaction with fever, chills, and
hemoglobinuria?
• Answer: Acute hemolytic transfusion reaction
• Rationale: An acute hemolytic reaction occurs when the recipient's antibodies
destroy transfused RBCs, typically from ABO incompatibility.
10. In blood banking, quality control for blood products includes testing for
bacterial contamination, ensuring proper storage temperature, and:
• Answer: verifying ABO/Rh typing
• Rationale: Blood banking quality control includes donor screening, component
processing verification, storage monitoring, and product testing.
11. Which of the following is a component of the blood banking quality control
process for blood products?
• Answer: Testing for bacterial contamination, ensuring proper storage
temperature, and verifying ABO/Rh typing
• Rationale: Blood banking quality control includes donor screening, component
processing verification, storage monitoring, and product testing.
12. What is the purpose of the direct antiglobulin test (DAT)?
• Answer: To detect antibodies or complement proteins bound to red blood cells
• Rationale: The DAT is used to diagnose hemolytic disease of the newborn and
autoimmune hemolytic anemia.
13. Which blood group system is most important in transfusion medicine?
• Answer: ABO and Rh
