Which statement best describes the role of the gel in SST tubes?

Which statement best describes the role of the gel in SST tubes?

• A. It Forms a Barrier Between Serum and Cells
• B. It Speeds Clotting
• C. It Acts as a Preservative
• D. It Changes Color on Centrifugation

Answer: (A)

The main idea here is what the gel in SST tubes does after centrifugation. The gel is a thixotropic separator that moves to sit between the serum (the liquid part you’ll test) and the cellular components (the clot and RBCs). By forming this physical barrier, it prevents cells from interacting with or altering the serum after spinning the sample down, which helps keep the analytes stable for accurate laboratory testing. This is why it’s the best description: the gel’s job is to separate and isolate the serum from cells, not to speed clotting, act as a preservative, or change color during centrifugation.

The main idea here is what the gel in SST tubes does after centrifugation. The gel is a thixotropic separator that moves to sit between the serum (the liquid part you’ll test) and the cellular components (the clot and RBCs). By forming this physical barrier, it prevents cells from interacting with or altering the serum after spinning the sample down, which helps keep the analytes stable for accurate laboratory testing.

This is why it’s the best description: the gel’s job is to separate and isolate the serum from cells, not to speed clotting, act as a preservative, or change color during centrifugation.