Which option lists the correct technique for mixing a tube with additives?

Which option lists the correct technique for mixing a tube with additives?

• A. Roll between palms
• B. Invert 6-8 times
• C. Shake vigorously
• D. Vortex

Answer: (B)

Mixing a tube with additives requires distributing the additive evenly through the blood without generating damaging shear forces. Inverting the tube end-to-end achieves gentle, thorough mixing: the blood and additive glide past each other when the tube is turned, not violently shaken. Six to eight inversions provide enough motion to distribute the additive evenly for most common additive tubes, ensuring proper anticoagulation or activation as required, while minimizing the risk of hemolysis or sample splashing. Rolling between the palms isn’t reliable for evacuated tubes and can risk uneven mixing or tube damage; shaking vigorously or vortexing introduces strong forces that can hemolyze cells and create bubbles, which can bias results. Follow manufacturer guidance, but six to eight inversions is a solid general rule for proper mixing.

Mixing a tube with additives requires distributing the additive evenly through the blood without generating damaging shear forces. Inverting the tube end-to-end achieves gentle, thorough mixing: the blood and additive glide past each other when the tube is turned, not violently shaken. Six to eight inversions provide enough motion to distribute the additive evenly for most common additive tubes, ensuring proper anticoagulation or activation as required, while minimizing the risk of hemolysis or sample splashing. Rolling between the palms isn’t reliable for evacuated tubes and can risk uneven mixing or tube damage; shaking vigorously or vortexing introduces strong forces that can hemolyze cells and create bubbles, which can bias results. Follow manufacturer guidance, but six to eight inversions is a solid general rule for proper mixing.