Phlebotomy Technician Practice Exam (NCPT/CPT)

What should be drawn last in the order of collection in a capillary draw?

1. EDTA

2. Blood gases

3. Green, gray, SST, serum

4. Heparin

The correct answer is: Green, gray, SST, serum

The last tube to be drawn in a capillary draw should be the preferred order of collection using the MiniCollect® capillary blood collection system green, gray, SST, serum. This order is important to ensure accurate test results and avoid cross-contamination. Option A, EDTA, is incorrect because it should be drawn first in order to prevent clotting. Option B, blood gases, should be drawn in the middle of the order after the other tubes have been collected. Option D, heparin, should be drawn before the SST tube as heparin can interfere with certain tests. Therefore, the correct order of collection is green, gray, heparin, SST, serum.