Certified Phlebotomy Technician Exam Special Specimen Collections 2 — Questions and Answers
Question 1: When collecting a blood culture specimen, how should the venipuncture site be cleaned?
- 70% isopropyl alcohol only
- Chlorhexidine or iodine scrub followed by alcohol (Correct answer)
- Soap and water followed by alcohol
- Betadine alone without additional alcohol
Correct answer: Chlorhexidine or iodine scrub followed by alcohol
Blood culture sites require a two-step antiseptic prep using chlorhexidine gluconate or povidone-iodine followed by 70% isopropyl alcohol to reduce contamination risk.
Question 2: A glucose tolerance test (GTT) requires the patient to fast for how long before the test begins?
- 4 hours
- 8–12 hours (Correct answer)
- 2 hours
- 24 hours
Correct answer: 8–12 hours
Patients must fast for 8–12 hours before a GTT to establish a true baseline fasting glucose level.
Question 3: Which tube is inoculated FIRST when collecting blood cultures using a butterfly needle?
- Aerobic bottle (Correct answer)
- Anaerobic bottle
- Either bottle; order doesn't matter
- EDTA tube to flush the line first
Correct answer: Aerobic bottle
With a butterfly needle, the aerobic bottle is inoculated first because air in the tubing fills it, preventing air from entering the anaerobic bottle.
Question 4: A 24-hour urine collection requires the patient to discard which specimen?
- The last void of the 24-hour period
- The first morning void at the start of collection (Correct answer)
- The first void after the midpoint of collection
- No void should be discarded
Correct answer: The first morning void at the start of collection
The first morning void is discarded to clear the bladder, and then the 24-hour timing begins with all subsequent voids collected.
Question 5: Which of the following is the correct method for collecting a neonatal bilirubin specimen?
- Venipuncture from the antecubital fossa
- Heel stick collected into an amber microtainer (Correct answer)
- Heel stick collected into a clear microtainer exposed to light
- Arterial puncture from the radial artery
Correct answer: Heel stick collected into an amber microtainer
Neonatal bilirubin is collected via heel stick into an amber (light-protected) microtainer because bilirubin degrades rapidly when exposed to light.
Question 6: What is the purpose of chilling a specimen for arterial blood gas (ABG) analysis?
- To prevent hemolysis during transport
- To slow cellular metabolism and preserve gas values (Correct answer)
- To prevent clotting in the syringe
- To keep the specimen from separating
Correct answer: To slow cellular metabolism and preserve gas values
Chilling an ABG specimen in ice water slows cellular metabolism, which would otherwise alter O2, CO2, and pH values during transport to the lab.
Question 7: For a therapeutic drug monitoring (TDM) trough level, when should blood be drawn relative to the drug dose?
- 30 minutes after the dose
- Immediately before the next scheduled dose (Correct answer)
- 2 hours after the dose
- At any time unrelated to dosing
Correct answer: Immediately before the next scheduled dose
A trough level is drawn immediately before the next scheduled dose, when the drug concentration is at its lowest point.
