Luminol & Oxidizing Solutions are chemicals used in chemiluminescent detection, a popular and highly sensitive protein detection method for Western Blotting. In this method, the enzyme known as horseradish peroxidase (HRP) conjugated to a secondary antibody reacts with a luminol, a chemiluminescent substrate. In the presence of an Oxidizing Solution, HRP oxidizes luminol to an excited state that emits light at 425 nm.