Overview antibody-mediated signal amplification. (a) Samples are dispensed using a microarrayer, target proteins are detected with highly specific antibodies and visualized by incubation with near-infrared dye-labeled secondary antibodies. Fast-Green FCF based normalization defines a spot-specific normalization factor. (b) Using the antibody-mediated signal amplification assay (AMSA) the antibody-based target protein detection step is followed by additional cycles of incubating with two different NIR-labeled species-specific secondary antibodies to increase the density of fluorescent signals. Both secondary antibodies were selected to recognize the respective other species.