Samples collected in EDTA must be well mixed at the time of draw and before sampling. The correct mixing time before sampling is five minutes on an aliquot mixer or, if they are mixed manually, a minimum of sixty inversions. However, avoid over mixing. Prolonged mixing on aliquot mixers causes hemolysis. As a safety precaution, always open evacuated tubes under a protective shield.
Residual vacuum causes aerosols.
Recommendations of the ICSH for EDTA anticoagulation of blood for blood cell counting and sizing. Amer J Clin Pathol. All rights reserved.