Antibody array detection of labeled antigens. 114 different antibodies were spotted onto poly-L-lysine coated slides 6-12 times each at a 375 μm spacing. Six protein mixes were labeled and detected according to the Materials and methods section. The inset in each panel highlights anti-Flag and anti-IgG spots, and the labels indicate the concentration of the antigen applied to each array. The images were normalized (see the Materials and methods section) and contrast adjusted to better show bright features.