Blood Specimen Collection

tourniquet

used to provide a barrier against venous blood flow to help locate a vein

3-4 inches; 1 minute

tourniquet should be applied _____ above the venipuncture site and left on for no longer than 1 minute before the venipuncture is performed

1. clot activators

2. anticoagulants

3. antiglycolitic agent

4. separator gel

additives in collection tubes

1. dipotassium ethylenediaminetetraacetate (K2 EDTA)

2. sodium citrate

3. heparin

anticoagulants

EDTA

prevents clotting by chelating calcium, an important cofactor in coagulation reactions