Collection ProceduresQuestion 35 of 100
An order requires a lavender EDTA tube and a gray fluoride tube only. Which sequence is correct and why?
a.Lavender first, because EDTA precedes the glycolytic inhibitor tube in the order of draw
b.Gray first, because it is the smallest tube
c.Either order, because neither additive affects the other
d.Gray first, because the fluoride preserves glucose better when drawn early
Explanation
In the standard sequence the EDTA tube always precedes the sodium fluoride and potassium oxalate tube, which is drawn last. Potassium oxalate carried backward into an EDTA tube can distort cell morphology and hematology results. Tube size and how early the fluoride is drawn have no bearing on the required order.
Law Reference: CLSI GP41Practice all 100 questions free — no signup required.
Related questions on this topic
- A requisition lists the patient name and tests but has no ordering provider and no collection priority. What should the phlebotomist do?
- How should the needle be positioned as it enters the skin during venipuncture?
- A phlebotomist has attempted venipuncture twice on the same patient without obtaining blood. What is the correct next step?
- Blood flow stops shortly after a good flash is seen. Which corrective action is appropriate?
- Which fingerstick technique is correct for an adult capillary glucose?
- A legal blood alcohol specimen is ordered. Which site preparation is required?
Last reviewed: · editorial process
PrepPass Editorial Team · Verified against NHA Certified Phlebotomy Technician (CPT) Exam · How we review