Most antibody array systems employ 1 of 2 non-competitive methods of immunodetection: single-antibody (label-based) detection and 2-antibody (sandwich-based) detection. The latter method, in which analyte detection requires the binding of 2 distinct antibodies (a capture antibody and a reporter antibody, each binding to a unique epitope), confers greater specificity and lower background signal compared with label-based immunodetection (where only 1 capture antibody is used and detection is achieved by chemically labeling all proteins in the starting sample). Sandwich-based antibody arrays usually attain the highest specificity and sensitivity (ng – pg levels) of any array format; their reproducibility also enables quantitative analysis to be performed.
Antibody array systems utilize either single-antibody or 2-antibody detection methods for immunodetection. The sandwich-based method, which involves two antibodies (a capture and a reporter antibody) binding to distinct epitopes of the analyte, offers greater specificity and lower background noise compared with the label-based method, where only one capture antibody is used. Sandwich-based arrays are known for their high sensitivity (ng – pg levels), reproducibility, and ability to perform quantitative analysis.