Western blot of GAP43 in rat cortical lysate showing specific immunolabeling of a band at ~50 kDa corresponding to Phospho-GAP43 (Ser41) polyclonal antibody (Product # PA1-4626) in the first lane (-). Phosphospecificity is shown in the second lane (+) where immunolabeling is completely eliminated by blot treatment with lambda phosphatase (1,200 units for 30 min).