Visual Mnemonics Gallery
Master critical phlebotomy concepts with visual learning aids
Order of Draw Mnemonic
"Blood Runs Green Lavender Gray"
| Tube Color | Additive | Common Tests | Fill Volume |
|---|---|---|---|
| Yellow/Black | SPS (Sodium Polyanethol Sulfonate) | Blood cultures | 10 mL |
| Blue | Sodium Citrate (3.2%) | PT, INR, PTT, Fibrinogen | 2.7 mL (exact fill critical) |
| Red/Gold | Clot Activator / SST (Gel) | CMP, TSH, Lipid Panel, Chemistry | 5-10 mL |
| Green | Lithium or Sodium Heparin | Stat Chemistry, Ammonia, Glucose | 5-7 mL |
| Lavender | EDTA (Ethylenediaminetetraacetic Acid) | CBC, Blood Type, HbA1c, Reticulocyte | 3 mL |
| Gray | Sodium Fluoride / Potassium Oxalate | Fasting Glucose, Lactic Acid, Lactate | 5 mL |
Exam Tip
- • Blue tube must be drawn second (after blood cultures) to prevent clotting
- • If blue tube is not collected, it can be drawn as the first tube without another tube being drawn
- • Never invert SST (red/gold) tubes before clotting - let them sit upright for 30-60 minutes
- • Lavender tube must be filled exactly to the line (7:1 ratio) or test results will be invalid
- • Gray tubes are always last as sodium fluoride preserves glucose