ECL (Enhanced Chemiluminescence) substrates are essential consumables used in Western blotting, a technique following gel electrophoresis, to detect proteins on blotting membranes. After proteins are transferred to the membrane and probed with antibodies, ECL substrates react with an enzyme, typically horseradish peroxidase (HRP), that is conjugated to the secondary antibody. This reaction produces a chemiluminescent signal, which can be captured by imaging systems or film. ECL substrates provide a highly sensitive and non-radioactive method for detecting even small amounts of target proteins, making them ideal for research in molecular biology, biochemistry, and medical diagnostics. With varying sensitivities, these substrates allow researchers to choose the right level of detection for their experiments, ensuring accurate protein identification and quantification.