Which of the following is true about SST tubes in chemistry testing?

• A. They Are Used to Collect Serum for Chemistry Tests
• B. They Are Used for Patient Blood Grouping
• C. They Are Used for Urine Analysis
• D. They Contain EDTA as Anticoagulant

Answer: (A)

SST tubes are designed to yield serum for chemistry testing. They contain a clot activator to speed clot formation and a thixotropic gel that sits between the serum and the clot when the sample is centrifuged. This gel creates a physical barrier, giving you clean, well-separated serum for accurate chemistry assays. The presence of EDTA or other anticoagulants is not characteristic of SST tubes; EDTA is found in lavender-top tubes. SST tubes are not used for urine analysis, which uses urine samples, and they are not the typical choice for blood grouping, which relies on different tube types and additives. So the statement that SST tubes are used to collect serum for chemistry tests is the most accurate reflection of their purpose.