BD Vacutainer^® Gel Tubes FAQs

The gel is composed of inert components, which are part of a polyester-based proprietary formulation.

The gel forms a physical barrier between serum or plasma and blood cells during centrifugation. It is important to note that after collection, BD SST^™ II Advance should be inverted five times, allowed 30 minutes clotting time, and centrifuged for 10 minutes at 1000-1300 RCF (g) in a swing bucket centrifuge. BD PST^™ II should be inverted 8 times, and centrifuged for 10 minutes at 1000-1300 RCF (g) in a swing bucket centrifuge.

BD SST^™ II Advance refers to the Serum Separator Tube containing clot activator and serum separator gel.
BD PST^™ II refers to the Plasma Separator Tube containing lithium heparin and plasma separator gel.

BD PST^™ can be centrifuged straightaway.
BD SST^™ must not be centrifuged until after 30 minutes clotting time has been allowed.

BD does not recommend re-centrifuging gel tubes once the barrier has formed.

The red cells freeze more slowly than the plasma/serum layer. When they freeze, they expand, pushing the gel upwards into the already-frozen liquid layer, which causes disruption of the gel barrier and subsequent mixing of the separated layers upon thawing.

The BD Vacutainer^® Serum Separation Transport Tube (SST^™) contains double the amount of gel compared to the regular SST^™ tubes. This provides a thicker barrier that remains intact when tubes are transported, thereby maintaining the quality of the sample for the lab analysis. It is intended for use primarily when specimens are collected and centrifuged in physician laboratories or other remote collection stations, and then transported back to the laboratory for analysis.

BD has not validated the BD SST^™ II Advance tubes for trace element testing. BD recommends using the Vacutainer^® Trace element tube specifically-designed for these analyses.

The silica particles that coat the walls of the BD SST^™ II Advance tube are the clot activator. Initial activation occurs when blood enters the tube and contacts the particles on the tube wall. To continue the activation process, it is necessary to gently mix the blood and particles by inverting the tube five times.

The walls of BD SST^™ II Advance serum separation tubes are coated with silica particles as a clot activator. The coating process creates a film on the tube surface that appears white and slightly cloudy. The tubes are fine to use. However, it is important to remember to invert the BD SST^™ II Advance tube at least five times after filling. This ensures adequate mixing of silica particles with the blood, which is required for optimal performance.

It is not recommended to use BD gel tubes for any tri-cyclic antidepressant drug testing. BD has done studies using BD SST^™ II Advance tubes for 16 other therapeutic drugs. The white paper (VS7049-1) may be accessed on the BD Library of Clinical Documentation.