APP and Alzheimer disease: Western blotting SDS-PAGE analyses followed by semi-quantitative densitometry were carried out on crude synaptosomal preparations of hippocampus and retina from animals of three experimental groups (littermate wild-type, vehicle-treated Tg-AD, Tg-AD+mAb) by probing with specific antibodies for APP (22C11), BACE1 and BIN1 (99D) (Figure 1).