Methodical and pre-analytical characteristics of a multiplex cancer biomarker immunoassay

Figure 3 Preanalytical factors: Storage after centrifugation at 4 °C. Behavior of biomarkers undergoing different pre-analytical conditions: Blood samples were stored for 0, 6, 24 and 48 h after centrifugation at 4 °C before definitive storage at -80 °C and measurement. Values are FI-based and depicted as recoveries corresponding to the values of directly centrifuged and frozen serum as reference. AFP: Alpha-fetoprotein; CA 125: Cancer antigen 125; CEA: Carcinoembryonic antigen; CV: Coefficient of variation; CYFRA 21-1: Cytokeratine 19-fragment; FGF2: Fibroblast growth factor-2; FI: Fluorescent intensity; HE4: Human epididymis protein 4; HGF: Hepatocyte growth factor; IL-6: Interleukin-6; MIF: Macrophage migration inhibitory factor; MR: Measuring range; Conc: Concentration; OPN: Osteopontin; QC 1: Quality control 1; SCF: Stem cell factor; sFas: Soluble Fas; sFasL: Soluble Fas-ligand; TGFα: Transforming growth factor-α; TNFα: Tumor necrosis factor-α; total PSA: Total prostate-specific antigen; TRAIL: Tumor necrosis factor related apoptosis-inducing ligand; VEGF: Vascular endothelial growth factor; β-HCG: β-human chorionic gonadotropin.