New biocompatible and haemocompatible perfluorocarbon emulsions are being developed to be used in in vivo and in vitro medical work. Several novel formulations of perfluorocarbon-based emulsions for use as respiratory gas-carrying fluids were developed and evaluated in relevant biological systems, including specially-developed in vitro bioassays. Some of the new emulsions incorporated novel and highly-purified fluoro-surfactants and newly-synthesised fluorinated stabilizers which significantly improved emulsion stability and increased storage time. The emulsions were steam sterilizable and storable at room temperature for over 1 year. In vivo gross toxicity assessments of selected emulsions at clinically-relevant doses showed satisfactory results. Some emulsions were assessed as perfusates of isolated vertebrate organs, where ex-vitro vital functions were markedly improved. Some of the novel fluoro-surfactants inhibited human platelet aggregation in vitro in a dose-dependent manner, suggesting novel and clinically-important potential applications as anti-thrombotic agents. Applications for this technology include: temporary blood replacement fluids in transfusion medicine; organ perfusion, preservation and protection solutions; extracorporeal pump-priming fluids; respiratory gas-carrying cell culture media supplements; anti-thrombotic and anti-haemostatic drugs.