Medical Laboratory Technologist
Certification Exam Questions And
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A
1. Which of the following is the most appropriate anticoagulant for a
routine hematology CBC?
A. Heparin
B. EDTA
C. Sodium citrate
D. Fluoride
B. EDTA
EDTA binds calcium and prevents clotting without significantly affecting
cell morphology, making it ideal for complete blood counts.
2. A patient has a prolonged PT but normal aPTT. Which factor
deficiency is most likely?
A. Factor VIII
B. Factor IX
C. Factor VII
D. Factor XII
C. Factor VII
PT measures the extrinsic pathway; a deficiency in factor VII prolongs PT
while aPTT remains normal.
3. In Gram staining, which step differentiates Gram-positive from Gram-
negative bacteria?
A. Primary stain
B. Mordant
, C. Decolorization
D. Counterstain
C. Decolorization
The decolorization step removes crystal violet from Gram-negative bacteria,
allowing the counterstain to color them pink, while Gram-positive remain
purple.
4. Which enzyme is measured to assess hepatocellular injury?
A. Amylase
B. ALT
C. ALP
D. GGT
B. ALT
Alanine aminotransferase is specific to hepatocytes and rises significantly
in hepatocellular injury.
5. A serum sample shows increased osmolarity and hypernatremia. The
patient is most likely experiencing:
A. SIADH
B. Diabetes insipidus
C. Addison’s disease
D. Hypothyroidism
B. Diabetes insipidus
Diabetes insipidus leads to water loss, concentrating sodium and increasing
serum osmolarity.
6. Which method is most accurate for identifying hemoglobin variants?
A. Peripheral smear
B. Electrophoresis
C. CBC
D. Reticulocyte count
B. Electrophoresis
Hemoglobin electrophoresis separates hemoglobin variants based on
charge and is the standard method for diagnosis.
, 7. Which of the following bacteria is catalase-positive?
A. Streptococcus pyogenes
B. Staphylococcus aureus
C. Enterococcus faecalis
D. Clostridium perfringens
B. Staphylococcus aureus
Staphylococci produce catalase, which breaks down hydrogen peroxide,
while streptococci and enterococci are catalase-negative.
8. A patient’s serum shows elevated LDH, AST, and ALT but normal
ALP. This pattern suggests:
A. Cholestasis
B. Hemolysis
C. Hepatocellular injury
D. Bone disease
C. Hepatocellular injury
AST and ALT elevations indicate hepatocyte damage, whereas ALP is
elevated in cholestasis.
9. Which anticoagulant is preferred for coagulation studies such as PT and
aPTT?
A. Heparin
B. EDTA
C. Sodium citrate
D. Oxalate
C. Sodium citrate
Citrate binds calcium reversibly, preserving coagulation factors and
allowing accurate testing.
10. A patient with macrocytic anemia and hypersegmented
neutrophils likely has:
A. Iron deficiency anemia
B. Vitamin B12 deficiency
C. Thalassemia minor
D. Chronic disease anemia
Certification Exam Questions And
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A
1. Which of the following is the most appropriate anticoagulant for a
routine hematology CBC?
A. Heparin
B. EDTA
C. Sodium citrate
D. Fluoride
B. EDTA
EDTA binds calcium and prevents clotting without significantly affecting
cell morphology, making it ideal for complete blood counts.
2. A patient has a prolonged PT but normal aPTT. Which factor
deficiency is most likely?
A. Factor VIII
B. Factor IX
C. Factor VII
D. Factor XII
C. Factor VII
PT measures the extrinsic pathway; a deficiency in factor VII prolongs PT
while aPTT remains normal.
3. In Gram staining, which step differentiates Gram-positive from Gram-
negative bacteria?
A. Primary stain
B. Mordant
, C. Decolorization
D. Counterstain
C. Decolorization
The decolorization step removes crystal violet from Gram-negative bacteria,
allowing the counterstain to color them pink, while Gram-positive remain
purple.
4. Which enzyme is measured to assess hepatocellular injury?
A. Amylase
B. ALT
C. ALP
D. GGT
B. ALT
Alanine aminotransferase is specific to hepatocytes and rises significantly
in hepatocellular injury.
5. A serum sample shows increased osmolarity and hypernatremia. The
patient is most likely experiencing:
A. SIADH
B. Diabetes insipidus
C. Addison’s disease
D. Hypothyroidism
B. Diabetes insipidus
Diabetes insipidus leads to water loss, concentrating sodium and increasing
serum osmolarity.
6. Which method is most accurate for identifying hemoglobin variants?
A. Peripheral smear
B. Electrophoresis
C. CBC
D. Reticulocyte count
B. Electrophoresis
Hemoglobin electrophoresis separates hemoglobin variants based on
charge and is the standard method for diagnosis.
, 7. Which of the following bacteria is catalase-positive?
A. Streptococcus pyogenes
B. Staphylococcus aureus
C. Enterococcus faecalis
D. Clostridium perfringens
B. Staphylococcus aureus
Staphylococci produce catalase, which breaks down hydrogen peroxide,
while streptococci and enterococci are catalase-negative.
8. A patient’s serum shows elevated LDH, AST, and ALT but normal
ALP. This pattern suggests:
A. Cholestasis
B. Hemolysis
C. Hepatocellular injury
D. Bone disease
C. Hepatocellular injury
AST and ALT elevations indicate hepatocyte damage, whereas ALP is
elevated in cholestasis.
9. Which anticoagulant is preferred for coagulation studies such as PT and
aPTT?
A. Heparin
B. EDTA
C. Sodium citrate
D. Oxalate
C. Sodium citrate
Citrate binds calcium reversibly, preserving coagulation factors and
allowing accurate testing.
10. A patient with macrocytic anemia and hypersegmented
neutrophils likely has:
A. Iron deficiency anemia
B. Vitamin B12 deficiency
C. Thalassemia minor
D. Chronic disease anemia
