b'Chemiluminescent western blot detectionChemiluminescence is the western blot detection methodChemiluminescent substrates differ from other substrates in of choice in many protein laboratories, as it provides highthat the light detected is a transient product of the reaction sensitivity and convenience for detection with film or digitalthat is only present while the enzymesubstrate reaction imaging equipment. Chemiluminescent substrates areis occurring (Figure 21). This contrasts with chromogenic popular because they offer several advantages over othersubstrates that produce a stable, colored product; these detection methods: colored precipitates remain on the membrane after the enzymesubstrate reaction has terminated. On aBlots can be reprobed to optimize detection, or tochemiluminescent western blot, the substrate is the limiting visualize a second protein reagent in the reaction; as it is exhausted, light productionCapable of detecting and quantitating a wide range ofdecreases and eventually ceases. A well-optimized protein concentrations procedure using the proper antibody dilutions will produce a stable output of light for several hours, allowingYield the greatest sensitivity of any availableconsistent and sensitive detection of proteins. There are detection method a variety of chemiluminescent substrates available with different formats and sensitivities. Figure 21. Overview of an enzymesubstrate reaction during chemiluminescent western blot detection.43'