How should a serum separator tube (SST) be handled after collection?

A serum separator tube (SST) is specifically designed to isolate serum from the blood after it has been collected. After blood collection, it's essential to properly handle the SST to ensure accurate test results. Allowing the tube to sit for approximately 30 minutes at room temperature enables proper clot formation, which is necessary for the effective separation of serum from cellular components when the tube is subsequently centrifuged.

During this time, the blood cells settle at the bottom of the tube, leaving the serum layer above. Gentle inversion helps to mix the gel separator with the serum without disturbing the clot or causing hemolysis. This step is crucial because if the serum is not separated from the cells correctly, it could affect the stability and integrity of the analytes being tested.

Immediate centrifugation is not ideal because it could lead to incomplete clot formation; thus, it is important to let the SST sit for a while first. Storing the tube in a cooler is unnecessary and can lead to inaccurate results, while shaking it vigorously can destroy blood cells and compromise results.