Routine Blood Collections is 28 of the 100 scored items on the NHA CPT exam. Answer 10 exam style questions on order of draw and tube additives and see exactly which concepts would cost you points on test day.
Start the 10 questions →What does ACD in a yellow top tube stand for, and what is it used for?
These questions cover additives, order of draw, tube mixing and coagulation tubes. Each one shows the correct answer and why every other option is wrong, so a miss tells you exactly what to review before the NHA CPT.
Prefer to read first? Every question from the practice set above, with the correct answer and why each wrong option is wrong.
Answer: A. Yellow top ACD tubes contain acid citrate dextrose, which preserves cells for tests such as HLA typing and paternity or DNA studies. Yellow SPS tubes are used for blood cultures.
Why not B: ACD stands for acid citrate dextrose; glucose is collected in gray fluoride tubes.
Why not C: Blood alcohol uses gray or specific tubes, not ACD.
Why not D: There is no such additive; serum comes from clot activator or plain tubes, not ACD.
Exam tactic: Yellow ACD = cell preservation; yellow SPS = cultures.
Answer: D. The order is serum separator, green heparin, lavender EDTA, then gray fluoride. Lavender is third.
Why not A: Green is second, right after the serum tube.
Why not B: Gray fluoride tubes are drawn last.
Why not C: The serum separator tube is first in this set.
Exam tactic: Serum, heparin, EDTA, fluoride.
Answer: B. Gray top tubes are generally inverted 8 to 10 times, following the manufacturer's instructions, to mix the additive fully.
Why not A: 25 inversions is well beyond the manufacturer's instructions and adds unnecessary handling; 8 to 10 is sufficient.
Why not C: 3 to 4 inversions are typical for light blue citrate tubes.
Why not D: One inversion does not mix the additive.
Exam tactic: Gray, green, lavender: 8 to 10.
Answer: A. The tubing of a winged set holds air. A discard tube (plain or another coagulation tube) is drawn first so the light blue tube fills to the correct 9 to 1 ratio.
Why not B: Tapping the tube does nothing about air in the tubing.
Why not C: An underfilled light blue tube gives an incorrect blood to citrate ratio and is rejected.
Why not D: Moving the coagulation tube out of order risks additive carryover.
Exam tactic: Butterfly plus blue first: discard tube.
Answer: A. The lithium in the anticoagulant contaminates the specimen and falsely raises a lithium result. Lithium levels are usually collected in a plain red top serum tube, or in a sodium heparin tube if the lab accepts it.
Why not B: Lithium in the tube does not cause clotting.
Why not C: Blood type is unaffected by tube additives.
Why not D: Volume is not the issue.
Exam tactic: Don't test for what's in the tube.
Answer: A. CLSI says tubes are filled from a syringe in the same order of draw used for evacuated tubes, through a safety transfer device. The reason is the same: it keeps additive from one tube from being carried into the next. The transfer is done promptly so the blood in the syringe does not start to clot.
Why not B: Additive carryover and clotting in the syringe still matter after collection.
Why not C: The order depends on additive type, not additive versus plain.
Why not D: Tube size is not the basis of the order.
Exam tactic: Syringe transfer: same order of draw.
Answer: A. Serum separator tubes with clot activator are generally inverted about 5 times to mix the activator, following manufacturer instructions.
Why not B: Shaking causes hemolysis.
Why not C: More inversions are not needed.
Why not D: The clot activator must be mixed with the blood.
Exam tactic: SST: 5 gentle inversions.
Answer: B. Current guidelines say a discard tube is generally not needed for routine PT or aPTT testing with a straight needle. A discard is needed with a winged set because of the tubing air.
Why not A: Two discard tubes only waste blood.
Why not C: A discard tube is not routinely needed here, and a full red top wastes blood.
Why not D: The light blue tube must always be filled to its fill line.
Exam tactic: Straight needle, routine PT: no discard.
Answer: D. Orange top rapid serum tubes contain a thrombin-based clot activator so serum is ready faster, often used for STAT chemistry.
Why not A: Sodium fluoride is in gray top tubes.
Why not B: SPS is in yellow top culture tubes.
Why not C: Lithium heparin is an anticoagulant in green tubes, giving plasma, not serum.
Exam tactic: Orange: thrombin, fast serum.
Answer: C. Blood cultures are drawn first so that no additive or microbial contamination from other tube stoppers can reach the sterile culture media.
Why not A: Temperature is not the reason for drawing them first; sterility is.
Why not B: Culture bottles contain culture media, not EDTA.
Why not D: Volume is not the reason for the order.
Exam tactic: Cultures first: sterility.
The free 20 question diagnostic covers all 5 areas of the NHA CPT outline and shows the 3 fixes worth the most points.
Take the free diagnosticSee all 22 Phlebotomy practice topics →