Order of Draw for Blood Collection
Blood Culture Bottles (Sterile, aerobic/anaerobic)
To prevent contamination.
Light Blue Top Tube – Sodium Citrate
For coagulation studies (PT, APTT, D-dimer).
Serum Tubes
Red Top – Plain (no additive)
Gold / Yellow / SST – With clot activator & gel separator
For serology, chemistry, immunology tests.
Green Top Tube – Heparin (Lithium / Sodium Heparin)
For plasma chemistry, electrolytes, blood gases.
Lavender / Purple Top Tube – EDTA
For hematology (CBC, HbA1c, ESR).
Gray Top Tube – Sodium Fluoride + Potassium Oxalate
For glucose testing.
Other Tubes (if required) – e.g., Dark Blue (Trace Elements), Yellow (ACD), Black (ESR special) depending on test requirements.
✅ Mnemonic to remember:
'Boys Love Ravishing Girls Like Greek Yogurt'
B – Blood culture
L – Light blue
R – Red / SST
G – Green
L – Lavender (EDTA)
G – Gray