Graphic representation of the fluorescence intensities obtained from (a) an ACPA-positive RA serum and (b) an ACPA-negative control serum. Magnifications are shown to the right. The upper red frame shows reactivity to Fibβ60-74, and the lower yellow frame shows reactivity to CEP1/Eno5-21. Within each frame, the left triplicate shows reactivity to the citrullinated peptide, whereas the right triplicate shows the reactivity to the native arginine-containing counterpart. Duplicate spots in the corners of both chips represent non-antigen-dependent fluorescence used for technical alignment of the chips.