title: Analytical performance evaluation of a particle-enhanced turbidimetric cystatin C assay on the Roche COBAS 6000 analyzer.
abstract: OBJECTIVE
  Cystatin C is a low molecular protein that has been proposed to estimate the glomerular filtration rate. Here we investigated the performance of the Roche cystatin C assay on the COBAS 6000 analyzer.
  
  
  METHODS
  We studied the imprecision, recovery, limit of detection and quantification, linearity and interferences. For method comparison, split sample aliquots were assayed using the described method and a Siemens cystatin C assay.
  
  
  RESULTS
  The assay displayed a low total imprecision and a good linearity over the entire range tested. Bilirubin and triglycerides did not interfere with the assay, and only a haemoglobin concentration higher than 6g/dl interfered with the assay. The assay agreed well with the Siemens assay.
  
  
  CONCLUSIONS
  The Roche cystatin C assay is an acceptable method for determining the cystatin C and the glomerular filtration rate estimate. On a COBAS 6000, the assay improves and simplifies the laboratory's workload.
authors.affiliation: U.G.C. Laboratorio Clínico, Hospital Nuestra Señora de la Merced, Avda. De la Constitución, 2. 41640-Osuna, Seville, Spain. manuel.conde.sanchez.sspa@juntadeandalucia.es
authors.forename: Manuel
authors.initials: M
authors.lastname: Conde-Sánchez
authors.forename: Esther
authors.initials: E
authors.lastname: Roldán-Fontana
authors.forename: Natalia
authors.initials: N
authors.lastname: Chueca-Porcuna
authors.forename: Susana
authors.initials: S
authors.lastname: Pardo
authors.forename: Juan
authors.initials: J
authors.lastname: Porras-Gracia
mesh_terms: D055316:Cystatin C / Q000097:blood*; D005919:Glomerular Filtration Rate; D006801:Humans; D016014:Linear Models; D009391:Nephelometry and Turbidimetry / Q000295:instrumentation / Q000379:methods*; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity
chemical_list: D055316:Cystatin C