ASCP Phlebotomy Technician Order of Draw and Additives 2

Question 1

What additive is found in yellow-topped blood culture tubes?

Accepted Answer

Sodium polyanethol sulfonate (SPS)

Answer

EDTA

Answer

Lithium heparin

Answer

Sodium fluoride

Question 2

Why must light blue-topped coagulation tubes be filled to the exact fill line?

Accepted Answer

To maintain the correct 9:1 blood-to-anticoagulant ratio

Answer

To prevent hemolysis

Answer

To ensure enough serum for testing

Answer

To prevent tube breakage during centrifugation

Question 3

Which tube additive works by activating clot formation rather than preventing it?

Accepted Answer

Clot activator (silica particles)

Answer

EDTA

Answer

Sodium citrate

Answer

Sodium heparin

Question 4

In the order of draw, why are EDTA (lavender) tubes drawn after heparin (green) tubes?

Accepted Answer

EDTA contamination would falsely affect electrolyte and enzyme results in heparin tubes

Answer

EDTA is more expensive than heparin

Answer

Green tubes need to be drawn first because they expire faster

Answer

There is no specific reason; the order is arbitrary

Question 5

What type of gel is found in gold-topped SST (serum separator) tubes and what is its function?

Accepted Answer

Thixotropic gel; it forms a barrier between serum and clot during centrifugation

Answer

Silicone gel; it prevents hemolysis

Answer

Acrylic gel; it preserves glucose levels

Answer

Polyethylene gel; it activates clotting

Question 6

A phlebotomist accidentally draws a green-topped tube before a light blue-topped tube. What should be done?

Accepted Answer

Discard the light blue tube and redraw it using a new venipuncture

Answer

Continue with the remaining draw and submit all tubes

Answer

Note the order error on the requisition and submit anyway

Answer

Switch the labels between the two tubes