What is the purpose of inversion in blood collection tubes?

Inversion of blood collection tubes serves the primary purpose of mixing the blood with additive agents present in the tubes. Many tubes contain anticoagulants or other additives that play a critical role in ensuring the proper processing of the blood sample. By inverting the tube several times after the blood is collected, these additives are evenly distributed throughout the blood, preventing clot formation and allowing for accurate test results.

For instance, if a tube contains an anticoagulant such as EDTA, proper mixing is essential to prevent the blood from clotting, as clotted samples would yield inaccurate laboratory results. Each tube typically has specific instructions regarding the number of inversions needed based on the type of additive it contains.

Inversions do not prevent contamination; they are not designed for sample cooling; and separating plasma from cells is a process that occurs after the sample is centrifuged, rather than during the blood collection phase.