Abstract: The present invention relates to an artificial synovial fluid composition that mimics the tribological properties of human, osteoarthritic synovial fluid (SF) for the main purpose of in vitro wear testing. There is described an artificial synovial fluid composition comprising: a) a mammalian serum having i) a total protein concentration of from about 10 to about 45 g/L; ii) an albumin fraction of from about 55% to about 80% w/w %; iii) an ?-1 globulin fraction of from about 3% to about 6% w/w %; iv) an ?-2 globulin fraction of from about 5% to about 10% w/w %; v) a ?-globulin fraction of from about 3% to about 20% w/w %; vi) a ?-globulin fraction of from about 5% to about 20% w/w %; vii) a calcium (Ca) concentration of from about 0.1 mmol/L to about 3 mmol/L; viii) a magnesium (Mg) concentration of from about 0.05 mmol/L to about 0.8 mmol/L; ix) an inorganic phosphate (P) concentration of from about 0.1 mmol/L to about 1.5 mmol/L; x) an iron (Fe) concentration of from about 0.001 mmol/L to about 0.