NHA Certified Phlebotomy Technician (CPT)Collection RoutineMedium
A phlebotomy technician is preparing to collect a blood specimen for a routine chemistry panel, including electrolytes and liver function tests. Which of the following tubes should the technician select?
- ALight blue top tube
- BGray top tube
- CGreen top tube
- DLavender top tube
Show answer & explanationAnswer & explanation
Correct answer: C. Green top tube
A green top tube contains heparin (lithium, sodium, or ammonium heparin), which acts as an anticoagulant. Heparinized plasma is commonly used for routine chemistry panels, including electrolytes and liver function tests, as it allows for rapid turnaround time by avoiding the clotting process.
Why the other options are wrong
- A. Light blue top tubes contain sodium citrate and are used for coagulation studies.
- B. Gray top tubes contain sodium fluoride and potassium oxalate and are used for glucose and alcohol levels.
- D. Lavender top tubes contain EDTA and are primarily used for hematology tests like CBC.
Green Top Tube Additive
A blood collection tube containing heparin, used to obtain plasma for various chemistry tests.
- Anticoagulant: Heparin.
- Specimen: Plasma.
- Common uses: Routine chemistry, electrolytes, liver function, renal function.
Memory trick: Green means go for general chemistry flow.