EDTA is an additive in tubes that are used to collect blood These tubes are generally lavender, purple, pink, gray, or navy blue This keeps blood from clotting so that analysis can be done on whole blood Tests that are run on these samples included the CBC (complete blood count), the ESR (erythrocyte sedimentation rate), and hemoglobin A1CBD Vacutainer Whole Blood Collection Tubes 3mL Lavender BD Box/100 For Whole Blood Collection K2 EDTA 72mg Spray Dried 3mL Tube with BD Hemogard Closure Clear Tube with Lavender Cap and Paper Label2 Protocol EDTA whole blood for DNA extraction Collection Delivery In collection tube Type of tube Standard 6 ml tube EDTA K2E, without gel, without protease inhibitors BD tube or equivalent Temperature Keep tubes at room temperature until prepared for storage Preparation Time until freezing Maximum 96 hours Centrifuge Not applicable Plastic K2 Edta Whole Blood Collection Tube Medline Industries Inc How much blood in edta tube