Blood collection tubes

Tube color

Anticoagulant

Common Uses

Red

None (Silica particles which
act as clot activator- separating
the serum from the clot)  

Typically used when serum is
required for analysis (Serum testing) -

1. LFT

2. KFT

3. Serum T3, T4, TSH

4. hCG

5. Viral marker (HIV, HCV,
HBsAg)

Light Blue

Sodium citrate

Coagulation testing-

1. PT

2. aPTT

3. INR (for monitoring patients
on warfarin)

4. D-dimer

Dark & Light
Green 

Dark green: Sodium heparin 

Light green: Lithium heparin

1. Osmotic fragility testing 

2. ABG studies 

Lavender
(Purple)

EDTA

Typically used when whole
blood is required for analysis-

1. CBC

2. Blood smears (for malaria)

3. Reticulocyte count

4. ESR

5. HbA1c

Grey

Potassium oxalate + Sodium
fluoride (inhibit glycolysis
enzyme “enolase”)

Glucose testing-

1. RBS

2. FBS

3. PPBS

4. GTT

Lactate