Figure 5
From: Prerequisites for cytokine measurements in clinical trials with multiplex immunoassays
Longitudinal assay performance using an internal control sample. Left panel shows variability in time of observed cytokine values of the internal control sample for IL-1β (A), IL-4 (B), I-L6 (C) and TNFα (D) in 50 consecutive runs covering a period of 12 months. Right-hand panel shows overlays of 4 separate standard curves of the corresponding cytokines.