Which sample handling step helps prevent hemolysis?

• A. Vigorous shaking to mix samples
• B. Draw with a very small gauge needle
• C. Expose sample to prolonged suction or mechanical trauma
• D. Gentle inversion to mix anticoagulants

Answer: (D)

Mixing the sample gently to distribute the anticoagulant while avoiding mechanical stress is the key to preventing hemolysis. When blood is drawn into a tube with an anticoagulant, gentle inversion ensures the additive is evenly mixed without creating the shear forces and turbulence that can rupture red blood cells. Vigorous shaking, prolonged suction or rough handling, and excessive mechanical trauma all increase the risk of hemolysis, which damages cells and can skew test results. Using a very small gauge needle can also contribute to cell damage during collection. Therefore, gentler inversion to mix the anticoagulant is the best practice to preserve cell integrity and accurate lab findings.