Collection ProceduresQuestion 10 of 100

A stat ammonia level is ordered. Which tube is used and where does it fall in the order of draw?

a.Lavender EDTA tube, drawn before the serum tube
b.Light blue citrate tube, drawn first
c.Green heparin tube, drawn after serum tubes and before EDTA
d.Gray fluoride tube, drawn before heparin

Explanation

Ammonia is collected in a heparin tube, and heparin tubes are drawn after serum tubes and before EDTA in the standard order. The specimen must also be placed on ice and delivered promptly because ammonia rises quickly at room temperature. EDTA, citrate and fluoride tubes are not appropriate for ammonia and none of them occupy the heparin position in the sequence.

Law Reference: CLSI GP41

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