What is the additive in a Lavender tube?

The additive in a Lavender tube is EDTA, specifically in the form of potassium EDTA. This anticoagulant is crucial because it helps to prevent blood from clotting by binding calcium ions in the blood. The presence of EDTA maintains the integrity of blood samples for various tests, including complete blood counts (CBC) and blood typing.

Potassium EDTA is particularly favored in hematology because it does not interfere with many laboratory tests, allowing for accurate results. While sodium heparin and lithium heparin are also anticoagulants used in other colored tubes, they serve different purposes and are used for specific tests, making them unsuitable for the Lavender tube's intended use. Thus, recognizing the specific type of EDTA in the Lavender tube is essential for phlebotomists when preparing samples for laboratory analysis.