Certified Phlebotomy Technician Exam Specimen Handling and Processing 2 — Questions and Answers
Question 1: A lavender-top tube is received in the lab without a label. What is the correct action?
- Process it immediately to avoid delays
- Label it from memory based on the requisition
- Discard it and request a redraw (Correct answer)
- Store it in the refrigerator until the patient is located
Correct answer: Discard it and request a redraw
Unlabeled specimens must be discarded and a redraw requested because mislabeled or unlabeled specimens are a critical patient safety risk.
Question 2: Which temperature range is correct for transporting most routine chemistry specimens?
- Frozen at -20°C
- Room temperature (20–25°C) (Correct answer)
- Refrigerated at 2–8°C
- Body temperature at 37°C
Correct answer: Room temperature (20–25°C)
Most routine chemistry specimens are transported at room temperature (20–25°C) unless otherwise specified by the test requirement.
Question 3: How long can a serum specimen typically remain at room temperature before centrifugation must occur?
- Up to 30 minutes
- Up to 2 hours (Correct answer)
- Up to 8 hours
- Up to 24 hours
Correct answer: Up to 2 hours
Most serum specimens should be centrifuged within 2 hours of collection to prevent analyte degradation and hemolysis.
Question 4: Which additive in a gray-top tube prevents glycolysis in glucose specimens?
- EDTA
- Sodium citrate
- Potassium oxalate and sodium fluoride (Correct answer)
- Lithium heparin
Correct answer: Potassium oxalate and sodium fluoride
Gray-top tubes contain potassium oxalate (anticoagulant) and sodium fluoride (glycolysis inhibitor) to stabilize glucose levels.
Question 5: A phlebotomist notices a clot in a lavender-top EDTA tube. What does this indicate?
- The tube was mixed correctly
- Insufficient mixing after collection (Correct answer)
- Excess EDTA was present
- The tube was centrifuged too quickly
Correct answer: Insufficient mixing after collection
Clotting in an EDTA tube indicates the specimen was not mixed adequately immediately after collection, allowing coagulation to begin.
Question 6: Which specimen requires protection from light during transport and processing?
- Serum potassium
- Whole blood CBC
- Bilirubin (Correct answer)
- Sodium
Correct answer: Bilirubin
Bilirubin is photosensitive and degrades rapidly when exposed to light, requiring amber bags or foil wrapping during transport.
Question 7: When centrifuging blood specimens, what is the typical relative centrifugal force (RCF) range used for routine separation?
- 100–200 × g
- 1,000–2,000 × g (Correct answer)
- 10,000–15,000 × g
- 50,000–100,000 × g
Correct answer: 1,000–2,000 × g
Routine blood specimen centrifugation uses approximately 1,000–2,000 × g (RCF) to separate cells from serum or plasma without damaging cells.
Certified Phlebotomy Technician Exam Specimen Handling and Processing 2
A lavender-top tube is received in the lab without a label.
What is the correct action?