NHA Certified Phlebotomy Technician (CPT)Specimen HandlingMedium
A phlebotomy technician receives an order for a lactic acid level. Which of the following steps is critical for proper specimen handling and transport?
- ACollect the specimen in a lavender-top EDTA tube and transport it without special handling.
- BCollect the specimen in a gray-top tube, place it immediately on ice, and transport it to the lab.
- CCollect the specimen in a red-top tube, centrifuge it, and then refrigerate the serum.
- DCollect the specimen in a tube with a gel separator and allow it to clot for 30 minutes at room temperature.
Show answer & explanationAnswer & explanation
Correct answer: B. Collect the specimen in a gray-top tube, place it immediately on ice, and transport it to the lab.
Lactic acid levels can increase rapidly if glycolysis continues in the blood cells after collection. To prevent this, a gray-top tube (containing an antiglycolytic agent like sodium fluoride) is used, and the specimen is immediately placed on ice to slow down metabolic processes.
Why the other options are wrong
- A. Lavender-top EDTA tubes are for hematology and do not contain the necessary additive for lactic acid preservation; 'without special handling' is incorrect.
- C. Red-top tubes lack antiglycolytic agents, and refrigeration alone may not be sufficient without proper additive.
- D. Gel separator tubes are not typically used for lactic acid, and clotting at room temperature would allow glycolysis to affect results.
Lactic Acid Specimen Handling
Lactic acid specimens require collection in a gray-top (fluoride/oxalate) tube and immediate chilling on ice to prevent glycolysis and ensure accurate measurement of true lactic acid levels.
- Use gray-top tube (sodium fluoride).
- Place immediately on ice slurry.
- Transport quickly to lab.
Memory trick: Lactic Acid: Gray ice stops the sugar's race.