These are small-volume blood collection tubes designed mainly for capillary sampling, especially when only a little blood is needed.
Key details:
Additive: EDTA (K2EDTA or K3EDTA)
Cap color: Usually purple / lavender
Sample type: Whole blood
Volume: ~250 μL – 500 μL (varies by manufacturer)
Mixing: Gently invert 8–10 times
Main uses:
Full Blood Count (FBC / CBC)
Differential count
Blood film / morphology
HbA1c (method-dependent)
ESR (micro methods)