What Tube Is Esr Drawn In

What Tube Is ESR Drawn In? An Overview

The erythrocyte sedimentation rate (ESR) is a simple, cost‑effective test that helps clinicians assess inflammation, infection, and certain malignancies. While the principle of the test is straightforward—measuring how fast red blood cells settle in a vertical column—the choice of tube is critical for accurate results. This article explains which tube is used for ESR, why it matters, and how to perform the test correctly.

Exploring the Basics of ESR Testing

ESR measures the distance (in millimeters) that erythrocytes fall in a vertical column of anticoagulated blood over one hour. The rate of sedimentation is influenced by plasma proteins, especially fibrinogen and immunoglobulins, which cause red cells to form rouleaux and settle faster. Because ESR is a nonspecific marker, it is most valuable when interpreted alongside clinical findings and other laboratory data.

Standard Tubes for ESR: Westergren vs. Wintrobe

Two tube types have historically been used for ESR:

Wintrobe tube – a narrow, 4 mm‑diameter glass tube that holds 1.5 mL of blood. It was the original standard but provides a limited sedimentation distance, which can reduce sensitivity in low‑range values.
Westergren tube – a wider, 4.5 mm‑diameter plastic tube that accommodates 3 mL of blood. The larger column allows a greater sedimentation distance, improving accuracy and reproducibility, especially for values above 20 mm/h.

Modern laboratories worldwide have adopted the Westergren tube as the preferred method, aligning with the recommendations of the International Council for Standardization in Haematology (ICSH).