Collection ProceduresQuestion 21 of 100

How should an EDTA tube be mixed immediately after collection?

a.Shake vigorously five times
b.Invert once and place upright in the rack
c.Invert gently 8 to 10 times
d.Do not mix; the additive dissolves on its own

Explanation

EDTA tubes require roughly 8 to 10 gentle inversions so the anticoagulant coats all the blood and microclots do not form. Vigorous shaking introduces mechanical trauma and hemolysis, which invalidates many tests. A single inversion or no mixing at all leaves clotted or clumped specimens that the laboratory must reject.

Law Reference: CLSI GP41

Practice all 100 questions free — no signup required.

Related questions on this topic

Last reviewed: · editorial process

PrepPass Editorial Team · Verified against NHA Certified Phlebotomy Technician (CPT) Exam · How we review
Report