‘Factors that influence autologous conditioned serum concentration in the horse’. With this research we are investigating possible factors that may affect the concentration of blood derived anti-inflammatory proteins such as interleukin 1 receptor antagonist protein (IRAP) in the horse. IRAP has been demonstrated to reduce the effects of osteoarthritis when administered locally into joints. This autologous or patient derived protein, harvested via whole blood culture in a commercially available system, is used world-wide as a conventional treatment of osteoarthritis in horses. By nature this autologous product that is specifically dependant on white cell function varies widely from animal to animal and with it also any ant-inflammatory potency. This research hopes to investigate methods in which to improve the product yield from whole blood culture systems and the protein’s stability in storage.