Specimen Processing and Handling Flashcards
7 cards from real Phlebotomy Test practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Specimen Processing and Handling flashcards as text
Which of the following best describes the correct technique for mixing an EDTA tube after venipuncture?
Answer: Gently invert 8–10 times
EDTA tubes should be gently inverted 8–10 times immediately after collection to ensure thorough anticoagulant mixing without causing hemolysis.
Why must lithium heparin tubes NOT be used for lithium level tests?
Answer: The additive lithium will falsely elevate the patient's lithium result
The lithium in lithium heparin additive would be added to the patient's own lithium, causing a falsely elevated serum lithium measurement.
A specimen tube that should be kept on ice during transport is a(n):
Answer: Arterial blood gas (ABG) syringe
ABG samples must be kept on ice to slow cellular metabolism and prevent gas exchange that would alter pH, pO₂, and pCO₂ values.
What is the purpose of the separator gel found in SST (serum separator) tubes?
Answer: It forms a stable barrier between serum and clot after centrifugation
The polyethylene glycol gel migrates during centrifugation to form a physical barrier between the serum layer and the clot, preserving serum integrity.
A 24-hour urine collection must be preserved with hydrochloric acid (HCl). Which test most commonly requires this preservative?
Answer: Urine catecholamines or metanephrines
Acid preservatives like HCl are required for 24-hour catecholamine and metanephrine collections to prevent oxidative breakdown of these compounds.
When a requisition shows 'QNS,' what does this mean and what action is taken?
Answer: Quantity not sufficient — the specimen volume is inadequate and the test cannot be performed; recollection is required
QNS (quantity not sufficient) means there is not enough specimen to run the requested test, requiring a new collection from the patient.
Plasma specimens differ from serum specimens because plasma:
Answer: Retains clotting factors that have been removed from serum
Plasma is obtained from anticoagulated blood and retains fibrinogen and other clotting factors, whereas serum is the liquid that remains after blood has clotted and those factors are consumed.