Clinical Laboratory Science Examination
Questions and Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
Question 1
The primary purpose of quality control (QC) in the clinical laboratory is to:
A. Increase sample volume
B. Reduce staffing needs
C. Eliminate instrument maintenance
D. Monitor the accuracy and precision of test results
Answer: D. Monitor the accuracy and precision of test results
Rationale: Quality control ensures laboratory test results remain reliable by
detecting analytical errors before patient results are reported.
Question 2
The phase of laboratory testing that includes patient identification and specimen
collection is the:
A. Analytical phase
B. Post-analytical phase
C. Reporting phase
D. Pre-analytical phase
Answer: D. Pre-analytical phase
,Rationale: The pre-analytical phase includes patient preparation, identification,
specimen collection, labeling, and transport.
Question 3
Which tube additive is commonly used for hematology testing?
A. Sodium fluoride
B. Sodium citrate
C. Lithium heparin
D. EDTA
Answer: D. EDTA
Rationale: EDTA preserves cellular morphology by chelating calcium and is the
preferred anticoagulant for complete blood counts.
Question 4
The anticoagulant used for coagulation studies is:
A. EDTA
B. Heparin
C. Potassium oxalate
D. Sodium citrate
Answer: D. Sodium citrate
Rationale: Sodium citrate reversibly binds calcium, preserving clotting factors for
coagulation testing.
Question 5
The most important step before collecting a blood specimen is:
A. Mixing the collection tube
B. Wearing gloves only
,C. Preparing the laboratory report
D. Correctly identifying the patient
Answer: D. Correctly identifying the patient
Rationale: Proper patient identification is essential to prevent specimen
identification errors and ensure patient safety.
Question 6
Hemolysis primarily interferes with laboratory results because it:
A. Lowers plasma proteins only
B. Prevents clot formation
C. Changes specimen color only
D. Releases intracellular substances into the specimen
Answer: D. Releases intracellular substances into the specimen
Rationale: Hemolysis releases intracellular components such as potassium and
lactate dehydrogenase, producing inaccurate results.
Question 7
Which laboratory department performs complete blood counts (CBCs)?
A. Clinical chemistry
B. Microbiology
C. Blood bank
D. Hematology
Answer: D. Hematology
Rationale: Hematology analyzes blood cells, including CBCs, differentials, and
blood smear evaluations.
Question 8
, Hemoglobin is primarily responsible for transporting:
A. Carbon dioxide only
B. Nutrients
C. Hormones
D. Oxygen
Answer: D. Oxygen
Rationale: Hemoglobin within red blood cells binds oxygen in the lungs and
transports it to tissues.
Question 9
Which blood cell is primarily responsible for oxygen transport?
A. Platelet
B. Neutrophil
C. Lymphocyte
D. Red blood cell
Answer: D. Red blood cell
Rationale: Red blood cells contain hemoglobin, which transports oxygen
throughout the body.
Question 10
The primary function of platelets is:
A. Oxygen transport
B. Antibody production
C. Hormone secretion
D. Blood clot formation
Answer: D. Blood clot formation
Rationale: Platelets are essential for primary hemostasis by forming the initial
platelet plug.
Questions and Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
Question 1
The primary purpose of quality control (QC) in the clinical laboratory is to:
A. Increase sample volume
B. Reduce staffing needs
C. Eliminate instrument maintenance
D. Monitor the accuracy and precision of test results
Answer: D. Monitor the accuracy and precision of test results
Rationale: Quality control ensures laboratory test results remain reliable by
detecting analytical errors before patient results are reported.
Question 2
The phase of laboratory testing that includes patient identification and specimen
collection is the:
A. Analytical phase
B. Post-analytical phase
C. Reporting phase
D. Pre-analytical phase
Answer: D. Pre-analytical phase
,Rationale: The pre-analytical phase includes patient preparation, identification,
specimen collection, labeling, and transport.
Question 3
Which tube additive is commonly used for hematology testing?
A. Sodium fluoride
B. Sodium citrate
C. Lithium heparin
D. EDTA
Answer: D. EDTA
Rationale: EDTA preserves cellular morphology by chelating calcium and is the
preferred anticoagulant for complete blood counts.
Question 4
The anticoagulant used for coagulation studies is:
A. EDTA
B. Heparin
C. Potassium oxalate
D. Sodium citrate
Answer: D. Sodium citrate
Rationale: Sodium citrate reversibly binds calcium, preserving clotting factors for
coagulation testing.
Question 5
The most important step before collecting a blood specimen is:
A. Mixing the collection tube
B. Wearing gloves only
,C. Preparing the laboratory report
D. Correctly identifying the patient
Answer: D. Correctly identifying the patient
Rationale: Proper patient identification is essential to prevent specimen
identification errors and ensure patient safety.
Question 6
Hemolysis primarily interferes with laboratory results because it:
A. Lowers plasma proteins only
B. Prevents clot formation
C. Changes specimen color only
D. Releases intracellular substances into the specimen
Answer: D. Releases intracellular substances into the specimen
Rationale: Hemolysis releases intracellular components such as potassium and
lactate dehydrogenase, producing inaccurate results.
Question 7
Which laboratory department performs complete blood counts (CBCs)?
A. Clinical chemistry
B. Microbiology
C. Blood bank
D. Hematology
Answer: D. Hematology
Rationale: Hematology analyzes blood cells, including CBCs, differentials, and
blood smear evaluations.
Question 8
, Hemoglobin is primarily responsible for transporting:
A. Carbon dioxide only
B. Nutrients
C. Hormones
D. Oxygen
Answer: D. Oxygen
Rationale: Hemoglobin within red blood cells binds oxygen in the lungs and
transports it to tissues.
Question 9
Which blood cell is primarily responsible for oxygen transport?
A. Platelet
B. Neutrophil
C. Lymphocyte
D. Red blood cell
Answer: D. Red blood cell
Rationale: Red blood cells contain hemoglobin, which transports oxygen
throughout the body.
Question 10
The primary function of platelets is:
A. Oxygen transport
B. Antibody production
C. Hormone secretion
D. Blood clot formation
Answer: D. Blood clot formation
Rationale: Platelets are essential for primary hemostasis by forming the initial
platelet plug.
