Using the Avidin: Biotin amplified system, greater sensitivity can be achieved for detecting any secondary antibody. The Avidin: Biotin amplified system introduces many enzymes to the target site providing signal amplification. When applied to Western blots to detect picogram amounts of antigens, the amplifiedAlkaline Phosphatase reagent and mouse or rabbit primary antibodies offers the best tool with no background on nitrocellulose or PVDF membranes. The signal can be visualized using either an AP chemiluminescent or a chromogenic substrate. The chemiluminescent signal can be captured on an X-ray film or on a Phosphorimaging equipment and the duration of exposure can extend the sensitivity of signal to detect proteins in the picogram range. ThisKit contains enough reagents to develop approximately twenty 100 cm2 blots.