What additive is present in the lavender tube used for blood collection?

The lavender tube used for blood collection contains EDTA (ethylenediaminetetraacetic acid) as its additive. EDTA functions as an anticoagulant, which means it helps prevent blood from clotting. This property makes it especially useful for specific tests, such as hematology assays, where the preservation of the cellular components of the blood is crucial for accurate results.

When blood is collected in a lavender top tube containing EDTA, it chelates calcium ions in the blood, which are essential for the coagulation cascade. By binding to these calcium ions, EDTA effectively stops the blood from clotting, allowing for accurate analysis of blood cells and other components for diagnostic purposes.

In contrast, other additives serve different purposes and are used in other types of tubes. For instance, sodium citrate is commonly found in light blue tubes for coagulation tests, heparin is used in green tubes for various plasma tests, and sodium oxalate is used in gray tubes typically for glucose testing. Understanding the specific role of EDTA and its importance in certain laboratory analyses helps to emphasize why it is selected as the additive in lavender top tubes.