Which statement is accurate regarding inversion for red top tubes?

Which statement is accurate regarding inversion for red top tubes?

• A. They must be inverted 5 to 8 times.
• B. They must be gently inverted.
• C. They require no inversion because they contain no additives.
• D. They should be shaken vigorously to mix.

Answer: (C)

Inversion is used to mix additives with the blood in a collection tube. Red-top tubes have no additives, so there’s nothing to mix. Because there’s no clot activator or anticoagulant to distribute, there’s no need to invert them. In fact, you generally avoid agitation to keep clotting and serum formation undisturbed. After collection, you let the blood clot and then centrifuge to obtain serum for testing. Shaking or repeatedly inverting could disturb the clot or the serum yield, so the correct point is that no inversion is required for red-top tubes.

Inversion is used to mix additives with the blood in a collection tube. Red-top tubes have no additives, so there’s nothing to mix. Because there’s no clot activator or anticoagulant to distribute, there’s no need to invert them. In fact, you generally avoid agitation to keep clotting and serum formation undisturbed. After collection, you let the blood clot and then centrifuge to obtain serum for testing. Shaking or repeatedly inverting could disturb the clot or the serum yield, so the correct point is that no inversion is required for red-top tubes.