What is the primary role of the thixotropic gel in blood collection tubes?

The primary role of thixotropic gel in blood collection tubes is to separate blood cells from serum. Thixotropic gel is a substance that, when subjected to stress (such as centrifugation), becomes fluid and allows for the separation of components within the blood sample. After the blood is drawn and centrifuged, the gel forms a barrier between the serum and the cellular components (such as red blood cells, white blood cells, and platelets). This separation is crucial for obtaining clear serum for various laboratory tests while preventing contamination from the cellular elements.

This functionality is particularly important in clinical settings, as it ensures that the serum can be easily withdrawn and analyzed without the introduction of cellular material, which might otherwise interfere with test results. The gel thus serves as a critical component in ensuring the integrity and reliability of blood test outcomes.