What is the additive found in lavender top tubes?

The correct answer is EDTA, which is the additive found in lavender top tubes. EDTA, or ethylenediaminetetraacetic acid, is an anticoagulant that works by binding calcium ions in the blood. This process prevents blood clotting, making it ideal for hematological studies, such as complete blood counts (CBCs) and blood smears. The use of EDTA allows for accurate cellular analysis by preserving the morphology and viability of the blood cells.

In the context of laboratory practices, tubes with different additives are used for specific tests, and knowing the correct additive is crucial for proper sample handling. Tubes with sodium heparin, citrate, or potassium citrate have different functions and applications in laboratory testing, like coagulation assays or specific biochemical tests, which is why they are not used in lavender top tubes. Therefore, understanding EDTA's role and the correct identification of tube colors and their additives is fundamental in phlebotomy and laboratory settings.