A set of cystatin C controls comprising recombinant human cystatin C in human serum. Each Control Set contains 3 x 1 mL of control level 1 (approximately 4.5 mg/L cystatin C) and 3 x 1 mL of control level 2 (approximately 1.1 mg/L cystatin C). The Control Set has been designed for use with Dako Cystatin C Immunoparticles (LX002) for the quantitative determination of cystatin C in human serum and plasma by turbidimetry and nephelometry.