Which additive is found in a Pink tube?

The pink tube is commonly associated with potassium EDTA as its additive. Potassium EDTA is a type of anticoagulant that effectively prevents blood from clotting by binding calcium ions in the blood. This property is particularly useful for tests that require whole blood or plasma, such as blood typing and crossmatching, which are critical in transfusion medicine.

EDTA works by chelating calcium, a necessary ion for the coagulation cascade, thus maintaining the integrity of the sample for accurate laboratory results. The specific use of potassium EDTA in pink tubes is often linked to blood bank procedures, reinforcing its role in ensuring that blood components are preserved for safe transfusion.

In contrast, lithium heparin and sodium heparin are anticoagulants used in other colored tubes designed for different tests, and they act through different mechanisms than EDTA. Because of the specific requirement for potassium EDTA in blood typing and compatibility testing, the pink tube is designated for these uses, highlighting its importance in phlebotomy and transfusion practices.