Research Article

Rheumatoid Factor and Its Interference with Cytokine Measurements: Problems and Solutions

Figure 1

Measured concentrations in PEG 6000-precipitated and in nonprecipitated samples at different spiked concentrations of IL-1β for plasma (a) and synovial fluid (b).
741071.fig.001a
(a)
741071.fig.001b
(b)