BD Vacutainer SST Advance Blood Collection Tube (Gold — Serum Separator)

After blood collection, invert the SST tube 5 times (end-over-end) to coat the blood with silica particles and activate clotting uniformly. Allow to clot at room temperature for a minimum of 30 minutes (do not refrigerate before clotting is complete — cold temperatures slow clotting and incomplete clotting before centrifugation produces fibrin in the serum). After 30 minutes, centrifuge at 1000-1300 RCF (relative centrifugal force) for 10 minutes in a swinging-bucket centrifuge at room temperature. In a fixed-angle centrifuge, centrifuge for 15 minutes at the same RCF. After centrifugation, the polymer gel will have migrated to form a stable barrier between the serum (above) and the cellular clot (below). The serum above the gel can then be poured, pipetted, or aspirated directly for laboratory analysis. Do not re-centrifuge after the gel barrier has formed.

The BD Vacutainer SST tube is suitable for the vast majority of routine clinical chemistry tests including: liver function panel; kidney function panel; lipid profile; thyroid function tests (TSH, T3, T4, fT4); cardiac markers (troponin, CK, CK-MB, myoglobin, pro-BNP); glucose; electrolytes; tumour markers (CEA, AFP, CA-125, CA-19-9, PSA); hormone assays; drug levels; vitamin D; and most serology immunoassay tests. The SST is not recommended for: certain therapeutic drug monitoring tests (some drug molecules adsorb to the gel — refer to specific drug TDM recommendations); trace element testing (BD does not validate SST tubes for trace metals such as lead, zinc, copper); and some specific protein tests where gel interference has been reported. When in doubt about test suitability, consult the test manufacturer's recommended sample collection tube.

Without a gel separator, serum collected in a plain tube must be carefully aliquoted — manually transferred from the tube into secondary cups or tubes — to separate it cleanly from the clot pellet. This aliquoting step adds time, requires additional secondary containers, increases the risk of cellular contamination during transfer, and creates additional sample identification steps. The gel separator eliminates all of this: after centrifugation, the gel barrier is in place and the serum sits cleanly above it. Automated laboratory analysers can directly aspirate serum from the gold SST tube through the closed BD Hemogard closure using the analyser's probe, without opening the tube — a closed-tube sampling technique that further reduces exposure risk and processing time. In high-throughput laboratory settings processing thousands of samples per day, the efficiency difference between gel and non-gel serum tubes is substantial.

BD specifically does not recommend re-centrifuging SST or other gel separator tubes after the gel barrier has formed. Once centrifuged and the gel has migrated to the serum-cell interface, the barrier is set. Re-centrifugation can disrupt the gel barrier, potentially re-mixing cellular contents with the serum or releasing cellular enzymes and haemoglobin into the serum — directly affecting subsequent test results for enzyme assays, haemoglobin measurements, and other analytes sensitive to haemolysis. If the first centrifugation is inadequate (centrifuge error, incorrect speed, incorrect time), and the gel has not yet fully migrated, the tube may be re-centrifuged once with careful monitoring. If the gel barrier is already in place, the sample should be regarded as the final centrifuged sample and handled accordingly.