Specimen Handling and Processing Flashcards
7 cards from real Certified Phlebotomy Technician Exam 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 Handling and Processing flashcards as text
Which of the following is a common cause of pre-analytical error in specimen handling?
Answer: Specimen collected from an IV line above an infusion site
Collecting blood from a site proximal to an IV infusion dilutes or contaminates the specimen with IV fluid, a classic pre-analytical error that invalidates results.
What is the maximum storage time for most whole blood specimens collected in EDTA at 2–8°C before CBCs become unreliable?
Answer: 24 hours
Most CBC parameters remain stable in EDTA at refrigerated temperatures for up to 24 hours, after which platelet swelling and morphology changes compromise results.
A serum separator tube (SST) must be inverted how many times after collection?
Answer: 5 times
SST tubes should be gently inverted 5 times to activate the clot activator coating while avoiding hemolysis from over-mixing.
Which test requires a fasting specimen for accurate results?
Answer: Fasting lipid panel
A fasting lipid panel requires the patient to fast for 9–12 hours before collection because dietary fat raises triglycerides and affects calculated LDL values.
What is the purpose of the gel separator in SST and PST tubes?
Answer: To form a physical barrier between cells and serum/plasma after centrifugation
The thixotropic gel in separator tubes migrates during centrifugation to form a stable physical barrier between the cellular layer and the serum or plasma layer.
A specimen labeled 'STAT' should be processed within what timeframe from receipt in the laboratory?
Answer: Within 30–60 minutes
STAT specimens require processing and result reporting within 30–60 minutes of receipt to meet clinical urgency standards and patient care needs.
Which action should be taken if a specimen arrives in the lab with visible clots in a tube that requires whole blood (e.g., EDTA)?
Answer: Reject the specimen and request a recollection
A clotted EDTA specimen must be rejected because clot formation means the anticoagulant failed to work, and results (especially CBC and coagulation-related tests) will be inaccurate.