Autologous conditioned serum (ACS) is a blood-derived product, produced through incubation and processing of a patient’s own blood. The incubation process results in a conditioned serum with high concentrations of IL-1Ra, other cytokines and growth factors. IL-1Ra, cytokines and growth factors have potential modulatory effects on osteoarthritis progression and potential anti-inflammatory effects. There are commercial specialised kits available for producing ACS, but it is also possible to produce ACS with serum tubes, an incubator and centrifuge.

In a study by the Norwegian School of Veterinary Science (Fjordbakk et al. 2014) it was shown that serum from blood incubated in plastic vacutainer tubes containing Z Serum Clot Activator contained similar levels of the cytokines and growth factors investigated as serum incubated in two specialised ACS containers. These results corroborate those of a previous study (Hraha et al 2011) and indicate that cytokine production may be a consequence of whole blood incubation rather than an effect of specialised ACS containers. Z Serum clot activated tubes were capable of producing the same output as specialised ACS containers if not more.