Phlebotomy Test Order of Draw and Additives 2

Question 1

Which tube is collected FIRST in the venipuncture order of draw?

Accepted Answer

Blood culture bottles

Answer

EDTA lavender top

Answer

Sodium citrate light blue top

Answer

Serum separator tube (SST)

Question 2

What additive is found in a royal blue top tube used for trace element testing?

Accepted Answer

EDTA or no additive (K2EDTA or plain)

Answer

Sodium heparin

Answer

Sodium citrate

Answer

Lithium heparin

Question 3

A gray top tube contains which combination of additives?

Accepted Answer

Sodium fluoride and potassium oxalate

Answer

EDTA and aprotinin

Answer

Thrombin and silica

Answer

Lithium heparin and gel separator

Question 4

In the order of draw, where does the EDTA (lavender) tube fall relative to heparin tubes?

Accepted Answer

After heparin tubes

Answer

Before heparin tubes

Answer

At the same position

Answer

Before light blue but after SST

Question 5

Which tube additive works by binding calcium ions to prevent coagulation?

Accepted Answer

EDTA

Answer

Sodium fluoride

Answer

Thrombin

Answer

Silica particles

Question 6

A phlebotomist draws a light blue top tube and notices the tube did not fill completely. What is the main concern?

Accepted Answer

The blood-to-additive ratio will be incorrect, affecting PT/INR results

Answer

Hemolysis will occur due to incomplete mixing

Answer

The tube will clot before reaching the lab

Answer

Glycolysis will continue in the underfilled tube

Question 7

Which color tube would be used when a physician orders a stat potassium level and the lab uses heparin plasma?

Accepted Answer

Green (lithium heparin)

Answer

Lavender (EDTA)

Answer

Red (no additive)

Answer

Gray (sodium fluoride)