The order of draw when collecting blood samples is: blood culture tube, coagulation tube, non-additive tube and additive tubes, as stated by the University of Utah. Using the proper order when collecting blood samples avoids cross-contamination of additives.
Collections in additive tubes must also occur in a particular order: sodium herapin, PST, EDTA, ACDA or ACDB, and oxalate or flouride, according to the University of Utah. If the phlebotomist does not thoroughly mix the additives in the tubes, the test results may not be accurate. Each tube has a different colored top to help the phlebotomist easily distinguish the type of tube.