Strion K2 EDTA vacuum blood collection tubes are used for collecting, preserving, and transporting blood samples for laboratory testing, particularly in hematology. These tubes utilize K2 EDTA (ethylenediaminetetraacetic acid) as an anticoagulant, which prevents blood clotting by binding calcium ions. The tubes are typically made of plastic and feature a vacuum to facilitate blood draw and are often color-coded with a lavender or purple cap