Phlebotomy Order of Draw and Additives Questions and Answers

Question 1

A phlebotomist needs to draw blood for a coagulation test, a complete blood count (CBC), and a serum chemistry panel. Which of the following represents the correct order of draw?

Accepted Answer

Light Blue, Red, Lavender

Answer

Light Blue, Lavender, Red

Answer

Red, Lavender, Light Blue

Answer

Lavender, Red, Light Blue

Question 2

Which of the following additives is correctly matched with its primary function in a blood collection tube?

Accepted Answer

EDTA - Anticoagulant that binds calcium

Answer

Sodium Fluoride - Clot activator

Answer

Heparin - Glycolysis inhibitor

Answer

Thrombin - Anticoagulant that binds thrombin

Question 3

A patient requires a blood draw for a Prothrombin Time (PT), a potassium level, and a blood alcohol level. The phlebotomist collects a light blue top tube, a green top tube, and a gray top tube. What is the consequence if the gray top tube is drawn before the green top tube?

Accepted Answer

The potassium level may be falsely elevated.

Answer

The PT result may be falsely shortened.

Answer

The blood alcohol level may be falsely decreased.

Answer

The specimen in the green tube may become hemolyzed.

Question 4

Why must blood culture tubes be drawn first in the order of draw?

Accepted Answer

To prevent contamination of the culture with additives from other tubes.

Answer

To prevent contamination of the culture with skin flora.

Answer

To ensure the tube's vacuum is at its strongest.

Answer

To allow the anticoagulant in the culture media to work immediately.

Question 5

A phlebotomist uses a butterfly needle to collect only a light blue top tube for a coagulation study. Which of the following is a necessary step to ensure an accurate result?

Accepted Answer

Draw a discard tube before the light blue tube.

Answer

Invert the tube vigorously 15 times.

Answer

Slightly underfill the light blue tube.

Answer

Warm the tube in an incubator before the draw.

Question 6

The additive in a green top tube is typically which of the following?

Accepted Answer

Lithium Heparin

Answer

Sodium Citrate

Answer

Potassium Oxalate

Answer

EDTA