In microcollection tubes, what position should the green tube generally be collected?

In microcollection tubes, what position should the green tube generally be collected?

• A. 1st
• B. 2nd
• C. 3rd
• D. 4th

Answer: (D)

The main concept here is protecting test accuracy by preventing cross-contamination of tube additives. The green microcollection tube contains heparin, an anticoagulant used for plasma chemistry tests. If it’s collected too early, residual heparin could carry over into tubes drawn after it and distort their results. To minimize this risk, the green tube is placed after the tubes that are drawn first (which may have no additive or different requirements) and before the tubes that rely on other additives, making it the fourth in the sequence. This placement helps preserve the integrity of both the serum/plasma tests and those that depend on specific anticoagulants.

The main concept here is protecting test accuracy by preventing cross-contamination of tube additives. The green microcollection tube contains heparin, an anticoagulant used for plasma chemistry tests. If it’s collected too early, residual heparin could carry over into tubes drawn after it and distort their results. To minimize this risk, the green tube is placed after the tubes that are drawn first (which may have no additive or different requirements) and before the tubes that rely on other additives, making it the fourth in the sequence. This placement helps preserve the integrity of both the serum/plasma tests and those that depend on specific anticoagulants.