VACUETTE® Serum Tubes
Serum tubes are coated with micronised silica particles, which activate clotting when tubes are gently inverted.
Serum tubes with gel contain a barrier gel that is present in the bottom of the tube. The specific gravity of this material lies between the blood clot and the serum. During centrifugation the barrier gel moves upward to the serum - clot interface, where it forms a stable barrier separating the serum from fibrin and cells. Serum may be aspirated directly from the collection tube, eliminating the need for transfer to another container. This barrier allows for the stability of certain parameters in the primary tube under the recommended storage conditions for up to 48 hours.
Serum tubes with beads contain polystyrene beads, which are present in the bottom of the tube. The specific gravity of the beads lies between that of the blood clot and serum. During centrifugation the beads move upwards to form a layer between the serum and blood clot