ASPT Blood Collection Equipment & Supplies

Question 1

Which tube color indicates the presence of EDTA as an additive?

Accepted Answer

Lavender/Purple

Answer

Lavender/purple-top tubes contain EDTA (ethylenediaminetetraacetic acid), an anticoagulant used for hematology tests such as the CBC.

Question 2

What is the primary purpose of yellow-top tubes containing sodium polyanethol sulfonate (SPS)?

Accepted Answer

Blood cultures

Answer

Yellow SPS tubes are used for blood culture collections because SPS inhibits complement, phagocytosis, and certain antibiotics that could interfere with microbial growth.

Question 3

Which needle gauge is most commonly used for routine adult venipuncture?

Accepted Answer

20–21 gauge

Answer

20–21 gauge needles are standard for routine adult venipuncture, providing adequate blood flow while minimizing patient discomfort and hemolysis.

Question 4

The green-top tube contains which anticoagulant?

Accepted Answer

Heparin

Answer

Green-top tubes contain heparin (sodium, lithium, or ammonium form), which prevents clotting by inhibiting thrombin activity.

Question 5

How many times should an EDTA tube be inverted after blood collection to ensure proper mixing?

Accepted Answer

8–10 times

Answer

EDTA tubes should be inverted 8–10 times to ensure complete mixing of the anticoagulant with the blood and prevent microclot formation.

(ASPT) American Society of Phlebotomy Technicians Practice Test

(ASPT) American Society of Phlebotomy Technicians Practice Test

ASPT Blood Collection Equipment & Supplies