Measurements of IL-1α, IL-1RA, CXCL-1/2 and hBD-1 from healthy skin. TAP’s containing capture antibody micro-arrays coated with anti-IL-1α, -IL-1RA, -CXCL-1/2 and -hBD-1 capture antibodies were incubated on skin for 1, 5, 15 or 30 minutes. IL-1α, IL-1RA, CXCL-1/2 and hBD-1 captured from skin were analyzed in spot-ELISA and signals were quantified by determining the pixel intensities of digitized spots. Signal intensities were compared to signals obtained using fixed concentrations of recombinant IL-1α, IL-1RA, CXCL-1/2 and hBD-1 captured in solution. In the graph, the apparent average concentration of IL-1α (Panel A), IL-1RA (Panel B) CXCL-1/2 (Panel C) and hBD-1 (Panel D) on skin of three persons has been plotted against incubation time on skin. Each data point in the graphs represents results of three spots analyzed on 6 TAP’s (N = 18). Y-axis: Apparent concentration of IL-1α, IL-1RA, CXCL-1/2 or hBD-1 on skin in ng/ml. X-axis: Incubation time on skin in minutes. Error bars on graph present standard deviation of analyzed data points (N = 18).