Phlebotomy Test Blood Collection Equipment and Supplies

Question 1

What is the standard needle gauge most commonly used for routine adult venipuncture?

Accepted Answer

21 gauge

Answer

The 21-gauge needle is the standard for routine adult venipuncture, providing adequate blood flow without causing excessive hemolysis.

Question 2

Which evacuated tube color contains EDTA as its anticoagulant and is most commonly used for CBC testing?

Accepted Answer

Lavender/purple

Answer

Lavender/purple top tubes contain EDTA, which chelates calcium to prevent clotting and is the additive of choice for hematology tests like CBCs.

Question 3

What is the primary purpose of applying a tourniquet during venipuncture?

Accepted Answer

To distend veins by restricting venous blood flow

Answer

A tourniquet restricts venous return, causing veins to distend and become more visible and palpable for easier needle access.

Question 4

What is the maximum recommended time a tourniquet should remain applied during venipuncture?

Accepted Answer

1 minute

Answer

A tourniquet should not remain applied for more than 1 minute because prolonged application causes hemoconcentration, which can falsely elevate cell counts and large-molecule analytes.

Question 5

Which antiseptic is most commonly used to cleanse the venipuncture site for routine blood collection?

Accepted Answer

70% isopropyl alcohol

Answer

70% isopropyl alcohol is the standard antiseptic for routine venipuncture; it must be allowed to air dry completely before needle insertion to prevent hemolysis and inaccurate results.

Phlebotomy Practice Test Practice Test

Phlebotomy Practice Test Practice Test

Phlebotomy Test Blood Collection Equipment and Supplies