CMLA Phlebotomy 2

Question 1

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

Accepted Answer

EDTA or no additive (trace-metal free)

Answer

Royal blue-top tubes are trace-metal free and may contain EDTA, heparin, or no additive depending on the test required.

Question 2

A patient has a hematoma at a previous venipuncture site. Where should the phlebotomist collect the next specimen?

Accepted Answer

A different site, avoiding the hematoma

Answer

A hematoma indicates extravasation of blood and can contaminate the specimen, so an alternate site must be selected.

Question 3

What is the correct angle of needle insertion for a standard venipuncture?

Accepted Answer

15–30 degrees

Answer

A 15–30 degree angle allows the needle to enter the vein without going through the posterior wall.

Question 4

Which tube is used to collect a specimen for a prothrombin time (PT) test?

Accepted Answer

Light blue (sodium citrate)

Answer

The light blue tube contains sodium citrate, which preserves clotting factors for coagulation studies like PT and aPTT.

Question 5

When performing a capillary puncture on an infant, which site is preferred?

Accepted Answer

Lateral or medial plantar surface of the heel

Answer

The heel is the preferred site for infant capillary puncture to avoid injury to bone, nerves, and tendons.

(CMLA) Certified Medical Laboratory Assistant Practice Test