MLS(ASCP) - MEDICAL LABORATORY SCIENTIST | VERIFIED ANSWERS AND QUESTIONS - MOST RECENT EDITION 2026/2027

MLS(ASCP) - MEDICAL LABORATORY SCIENTIST
| VERIFIED ANSWERS AND QUESTIONS - MOST
RECENT EDITION 2026/2027




MLS(ASCP) Medical Laboratory Scientist




1. Which analyte is the primary extracellular cation?
A. Potassium
B. Sodium
C. Calcium
D. Magnesium
ANSWER : B. Sodium
Explanation: Sodium is the major extracellular cation and plays a major role in
fluid balance and osmolality.
2. Which analyte is the major intracellular cation?
A. Sodium
B. Chloride
C. Potassium
D. Bicarbonate
ANSWER : C. Potassium
Explanation: Potassium is the predominant intracellular cation and is essential
for membrane potential and neuromuscular function.
3. Which enzyme is most closely associated with hepatocellular injury?
A. ALT

, B. Amylase
C. CK
D. ALP
ANSWER : A. ALT
Explanation: Alanine aminotransferase is concentrated in hepatocytes and is
commonly used to evaluate hepatocellular injury.
4. Which enzyme is more specific for pancreatic injury?
A. ALP
B. Lipase
C. AST
D. CK
ANSWER : B. Lipase
Explanation: Lipase is relatively specific for pancreatic injury and often
increases during acute pancreatitis.
5. Which specimen is generally preferred for arterial blood gas analysis?
A. Serum
B. EDTA plasma
C. Heparinized whole blood
D. Citrated plasma
ANSWER : C. Heparinized whole blood
Explanation: Arterial blood collected in balanced heparin is commonly used for
blood gas testing.
6. What is the principal extracellular buffer?
A. Phosphate
B. Hemoglobin
C. Bicarbonate
D. Protein
ANSWER : C. Bicarbonate
Explanation: The carbonic acid-bicarbonate system is the principal extracellular
buffering system.
7. Which hormone lowers blood glucose?
A. Cortisol
B. Glucagon

, C. Insulin
D. Epinephrine
ANSWER : C. Insulin
Explanation: Insulin promotes cellular glucose uptake and storage, lowering
blood glucose concentration.
8. Which hormone increases blood glucose during fasting?
A. Insulin
B. Glucagon
C. Calcitonin
D. Aldosterone
ANSWER : B. Glucagon
Explanation: Glucagon stimulates glycogenolysis and gluconeogenesis,
increasing blood glucose.
9. Which test is commonly used to assess long-term glycemic control?
A. Troponin
B. HbA1c
C. Amylase
D. Bilirubin
ANSWER : B. HbA1c
Explanation: Hemoglobin A1c reflects average blood glucose exposure over
approximately 2 to 3 months.
10.Which bilirubin fraction is water soluble?
A. Unconjugated bilirubin
B. Indirect bilirubin
C. Conjugated bilirubin
D. Free bilirubin
ANSWER : C. Conjugated bilirubin
Explanation: Hepatic conjugation makes bilirubin water soluble and allows
excretion into bile.
11.Which protein is most abundant in plasma?
A. Fibrinogen
B. Albumin
C. Transferrin
D. Immunoglobulin G

, ANSWER : B. Albumin
Explanation: Albumin is the most abundant plasma protein and contributes
substantially to oncotic pressure.
12.Which analyte is most affected by prolonged tourniquet application?
A. Sodium
B. Total protein
C. Chloride
D. Glucose
ANSWER : B. Total protein
Explanation: Prolonged venous stasis causes hemoconcentration, increasing
protein and other protein-bound analytes.
13.Which electrolyte is most vulnerable to pseudohyperkalemia from
hemolysis?
A. Sodium
B. Potassium
C. Chloride
D. Calcium
ANSWER : B. Potassium
Explanation: Red blood cells contain much more potassium than plasma, so
hemolysis releases potassium into the specimen.
14.Which kidney marker is routinely used to estimate renal filtration?
A. Creatinine
B. ALT
C. Bilirubin
D. Amylase
ANSWER : A. Creatinine
Explanation: Serum creatinine is commonly used to assess renal filtration and
calculate estimated GFR.
15.Which analyte is commonly measured to assess pancreatic function?
A. Lipase
B. ALP
C. GGT
D. CK-MB