Which statement about red top tubes is true?

Which statement about red top tubes is true?

• A. They contain no additives.
• B. They contain anticoagulants.
• C. They contain clot activator.
• D. They require inversion despite no additives.

Answer: (A)

Red top tubes are additive-free, so they contain no anticoagulants or clot activators. Because there’s nothing added to prevent clotting or to promote it, blood drawn into a red top tube will clot naturally and serum is obtained after centrifugation. This makes them useful for tests that require serum rather than plasma. Since there’s nothing to mix, these tubes usually don’t need to be inverted. Statements claiming they contain anticoagulants or clot activators or that they must be inverted despite having no additives aren’t accurate.

Red top tubes are additive-free, so they contain no anticoagulants or clot activators. Because there’s nothing added to prevent clotting or to promote it, blood drawn into a red top tube will clot naturally and serum is obtained after centrifugation. This makes them useful for tests that require serum rather than plasma. Since there’s nothing to mix, these tubes usually don’t need to be inverted. Statements claiming they contain anticoagulants or clot activators or that they must be inverted despite having no additives aren’t accurate.