What are Black Top ESR Tubes used for?

They are used for erythrocyte sedimentation rate (ESR) testing to evaluate systemic inflammation.

Why is sodium citrate used in ESR tubes?

It binds calcium ions to prevent clotting and ensures accurate red blood cell sedimentation.

What is the correct blood-to-additive ratio?

Black Top ESR Tubes require a strict 4:1 ratio for accurate and reproducible results.

How should ESR tubes be handled?

They should be gently inverted 5–8 times and tested within 1 hour for optimal accuracy.