Chemiluminescent substrates provide a higher degree of sensitivity than other substrates to enable lower limits of detection to be achieved in Western Blot assays. The increase in sensitivity requires more vigilance during the optimization process through the proper selection of the luminol substrate, antibody/antigen titers and blockers. Surmodics provides multiple 2-component HRP chemiluminescent substrates with various intensities to allow the assay developer to choose the appropriate substrate for the application. Benefits: 1) Picogram to femtogram levels of sensitivity 2) High signal-to-noise ratios