NCCT Equipment, Tubes, and Additives 2

Question 1

What is the function of sodium fluoride in a gray-top tube?

Accepted Answer

Inhibits glycolysis to preserve glucose levels

Answer

Sodium fluoride is a glycolytic inhibitor that prevents blood cells from consuming glucose, preserving accurate glucose levels in the specimen.

Question 2

Which tube color contains the anticoagulant EDTA?

Accepted Answer

Lavender/purple

Answer

Lavender (purple) top tubes contain EDTA (ethylenediaminetetraacetic acid), which is the standard anticoagulant for hematology testing.

Question 3

What is the purpose of a butterfly (winged infusion) needle set?

Accepted Answer

To access small or difficult veins with greater control

Answer

Butterfly needles have flexible tubing and a smaller needle, allowing better control and access to small, fragile, or rolling veins.

Question 4

What does the thixotropic gel in a serum separator tube (SST) do during centrifugation?

Accepted Answer

Forms a barrier between serum and the cell clot

Answer

During centrifugation, the thixotropic gel migrates to the interface between the serum and the clot, forming a stable physical barrier that prevents mixing.

Question 5

When using a syringe for blood collection, what is the correct method for transferring blood to evacuated tubes?

Accepted Answer

Attach a transfer device and allow the vacuum to pull blood in

Answer

A syringe transfer device is attached to replace the needle, and the tube's vacuum draws blood in, reducing hemolysis risk and preventing needle stick injuries.

NCCT - National Certified Phlebotomy Technician Exam Practice Test

NCCT - National Certified Phlebotomy Technician Exam Practice Test

NCCT Equipment, Tubes, and Additives 2