In the microcollection system, what position should the gold tube be collected?

• A. First
• B. Fourth
• C. Second
• D. Third

Answer: (D)

The question tests how you order draws in a microcollection system to protect test results from additive carryover and ensure proper serum production. The gold tube contains a clot activator and a gel for serum separation, so it’s used to obtain serum after the blood has clotting started. Filling it at the third position helps minimize the chance that additives from the earlier tubes (or any residuals on the needle) contaminate the serum sample, and it aligns with keeping tubes that could alter clotting or later chemistry tests from affecting the serum tube.

In practice, the two tubes drawn before the gold tube are chosen to avoid introducing substances that could interfere with clotting or with subsequent serum testing. Placing the gold tube third thus balances the need for clean serum with the overall sequence that minimizes additive cross-over.