Figure 1.

Basic principle of a protein expression profiling array and different detection schemes. (A) Capture agents with different analyte specificity are immobilized on a surface. (B) Incubation with protein samples leads to specific capture of target proteins in a concentration dependent manner. (C) After washing, the specifically bound target protein can be visualized by a variety of detection schemes, such as (1) direct fluorescence labeling of the analyte with a fluorophore (F) (labeled prior to the experiment), (2) detection of the target protein by a fluorescently-labeled detection antibody or (3) an enzyme-conjugated detection antibody, allowing an ELISA-based detection with a fluorescent, chemiluminescent or colorimetric readout (S = substrate, P = product).