Which description is accurate about tube inversion after filling?

• A. Only tubes with clot activators require inversion.
• B. All tubes except red top tubes require inversion.
• C. Only tubes with gel separators require inversion.
• D. Blue top tubes require inversion regardless.

Answer: (B)

Mixing the blood with the tube’s additive is essential for the test to be accurate. Inverting after filling distributes any anticoagulant or clot activator through the specimen, and helps gel-containing tubes separate properly later. Red-top tubes have no additive, so there’s nothing to mix, and inversion isn’t needed. Because every other type of tube contains something that changes how the blood behaves or preserves it, inversion is necessary for those tubes. That’s why the description stating that all tubes except red top tubes require inversion is the best fit.