NCCT National Certified Phlebotomy Technician MCQ 3

Question 1

A complete blood count (CBC) specimen must be collected in which tube?

Accepted Answer

Lavender/purple (EDTA)

Answer

CBC specimens are collected in lavender/purple EDTA tubes because EDTA best preserves blood cell morphology and prevents platelet clumping.

Question 2

Which of the following is an example of a timed specimen that must be drawn at a specific time?

Accepted Answer

Peak drug level (e.g., vancomycin)

Answer

Peak drug levels must be drawn at a specific time after medication administration to measure the highest concentration.

Question 3

What is the purpose of the buffy coat layer visible after blood centrifugation?

Accepted Answer

It is a thin layer of white blood cells and platelets between plasma and red blood cells

Answer

The buffy coat is a thin whitish layer between the plasma/serum and the packed red blood cells, consisting of white blood cells and platelets.

Question 4

Which anticoagulant prevents clotting by inhibiting thrombin through activation of antithrombin III?

Accepted Answer

Heparin

Answer

Heparin prevents clotting by binding to and activating antithrombin III, which in turn inhibits thrombin and several other coagulation factors.

Question 5

A specimen for erythrocyte sedimentation rate (ESR) should be collected in which tube?

Accepted Answer

Lavender (EDTA) or black (sodium citrate for ESR)

Answer

ESR can be performed on blood collected in a lavender EDTA tube or a specialized black-top tube containing sodium citrate specifically formulated for sedimentation rate testing.

NCCT - National Certified Phlebotomy Technician Exam Practice Test

NCCT - National Certified Phlebotomy Technician Exam Practice Test

NCCT National Certified Phlebotomy Technician MCQ 3