NHA Certified Phlebotomy Technician (CPT)Collection RoutineEasy
A phlebotomy technician is preparing to collect a blood specimen for a routine chemistry panel, including electrolytes and glucose. Which of the following tubes should the technician choose?
- ALight blue top tube
- BGreen top tube
- CLavender top tube
- DRed top tube
Show answer & explanationAnswer & explanation
Correct answer: B. Green top tube
For routine chemistry panels and electrolytes, a green top tube containing heparin is typically used. Heparin prevents clotting and allows for plasma analysis, which is suitable for these tests.
Why the other options are wrong
- A. Light blue top tubes contain sodium citrate and are used for coagulation studies.
- C. Lavender top tubes contain EDTA and are primarily used for hematology tests like CBC.
- D. Red top tubes are plain or contain a clot activator and are used for serum chemistry or blood banking, but not typically for routine chemistry panels requiring plasma.
Green Top Tube
A blood collection tube containing heparin, used to obtain plasma for chemistry tests.
- Contains anticoagulant heparin (lithium, sodium, or ammonium heparin).
- Prevents blood clotting by inhibiting thrombin.
- Yields plasma after centrifugation.
- Commonly used for routine chemistry, electrolytes, and STAT chemistry.
Memory trick: Remember the rainbow of tubes for different tests!