Order of Draw

When using a winged blood collection setfor venipuncture and a coagulation (citrate) tube is the first specimen tube to be drawn, a discard tube should be drawn first. The discard tube must be used to fillthe blood collection set tubing’s “dead space” with blood but the discard tube does not need to be completely filled. This important step will ensure proper blood- to-additive ratio. The discard tube should be a nonadditive orcoagulation tube

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Laboratory Survival Guide

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