Certified Phlebotomy Technician Exam Specimen Handling and Processing 5

Question 1

Which of the following is a common cause of pre-analytical error in specimen handling?

Accepted Answer

Specimen collected from an IV line above an infusion site

Answer

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.

Question 2

What is the maximum storage time for most whole blood specimens collected in EDTA at 2–8°C before CBCs become unreliable?

Accepted Answer

24 hours

Answer

Most CBC parameters remain stable in EDTA at refrigerated temperatures for up to 24 hours, after which platelet swelling and morphology changes compromise results.

Question 3

A serum separator tube (SST) must be inverted how many times after collection?

Accepted Answer

5 times

Answer

SST tubes should be gently inverted 5 times to activate the clot activator coating while avoiding hemolysis from over-mixing.

Question 4

Which test requires a fasting specimen for accurate results?

Accepted Answer

Fasting lipid panel

Answer

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.

Question 5

What is the purpose of the gel separator in SST and PST tubes?

Accepted Answer

To form a physical barrier between cells and serum/plasma after centrifugation

Answer

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.

Certified Phlebotomy Technician Exam Practice Test

Certified Phlebotomy Technician Exam Practice Test

Certified Phlebotomy Technician Exam Specimen Handling and Processing 5