← Open Exam Hub

Phlebotomy Tube Colors & Additives: What Each Tube Tests

October 18, 2026 · 10 min

Chapters

  1. Colors Are a Code
  2. Three Jobs for an Additive
  3. Light Blue: Sodium Citrate
  4. Red and Gold: Clot Activator and Gel
  5. Green: Heparin
  6. Lavender and Pink: E D T A
  7. Gray: Fluoride and Oxalate
  8. Other Tubes You'll See
  9. The Summary Table
  10. How N H A and N C C T Test Tubes
  11. Practice Questions
  12. Recap

Audio from the Open Exam Hub video of the same name; the video shows the numbers and practice questions on screen.

Free phlebotomy cheat sheet
What is inside each blood collection tube and what it is used for: light blue sodium citrate (coagulation), red and gold clot-activator and gel serum tubes, green heparin, lavender and pink EDTA, gray fluoride/oxalate, plus the yellow culture tube. Organized by what an additive does (prevent clotting, encourage clotting, preserve), with a summary table, how the NHA CPT test plan and NCCT NCPT plan test colors and additives, and 5 original practice questions. Typical test uses are general lab practice; your lab's directory wins. Facts as of October 2026; independent, not affiliated with NHA, NCCT or any tube maker.

Phlebotomy cheat sheet
Phlebotomy study plan
Free phlebotomy practice
Free practice questions, study guides and cheat sheets, no signup

Chapters
0:00 Colors Are a Code
1:10 Three Jobs for an Additive
2:06 Light Blue: Sodium Citrate
2:59 Red and Gold: Clot Activator and Gel
3:53 Green: Heparin
4:32 Lavender and Pink: E D T A
5:27 Gray: Fluoride and Oxalate
6:04 Other Tubes You'll See
6:40 The Summary Table
7:06 How N H A and N C C T Test Tubes
7:39 Practice Questions
9:29 Recap

Exam facts are from the official NHA and NCCT pages as of 2026-10-27. Fees and rules can change, so confirm on the official site before you enroll. Open Exam Hub is an independent study resource, not affiliated with NHA, NCCT or any tube maker. Practice questions are not from a real exam. Narration is an AI-generated voice.

Music
"Carefree" Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 4.0 License
creativecommons.org/licenses/by/4.0

"Friday Morning" Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 4.0 License
creativecommons.org/licenses/by/4.0

"Fresh Air" Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 4.0 License
creativecommons.org/licenses/by/4.0

Sound effects: Kenney (kenney.nl), CC0.

#Phlebotomy #TubeColors #NHA