Question 71

Moving the tubes in a figure-eight motion 4 to 8 times after collection

Inverting tubes using a figure-eight motion 4 to 8 times is the best method to ensure proper mixing of the anticoagulant with the blood and prevent clotting.

A) Shaking the tubes 4 to 8 times after collection

Shaking the tubes can cause hemolysis of the blood sample, which can lead to inaccurate test results. This method is not recommended as it does not effectively mix the anticoagulant with the blood.

B) Moving the tubes in a figure-eight motion 4 to 8 times after collection

This method is effective because it gently mixes the blood and anticoagulant without damaging the blood cells. The figure-eight motion provides a thorough and consistent mixing action, which is essential to prevent clotting.

C) Rolling the tubes between the palms of the hands 4 to 8 times after collection

While rolling can mix the contents, it may not be as effective in ensuring even distribution of the anticoagulant throughout the blood sample. This method lacks the controlled motion that a figure-eight provides, making it less reliable.

D) Passing the tubes from hand to hand 4 to 8 times after collection

Passing the tubes from hand to hand does not provide adequate mixing of the blood with the anticoagulant. This method is too passive and may not sufficiently prevent clotting, making it an ineffective choice.

Conclusion

The figure-eight motion is the superior technique for inverting tubes, as it maximizes the contact between the anticoagulant and the blood, effectively preventing clot formation. Other options either risk damaging the sample or do not provide the necessary mixing, underscoring why option B is the correct and preferred method.