Immunohistochemistry showing granular localization of GDNF in rat adrenal (A) and cultured bovine chromaffin (B) cells.A, Confocal fluorescence microscopy of anti-chromogranin A (monoclonal, green), anti-GDNF (polyclonal,red), and its double detection (yellow) using paraffin sections of embryonic rat adrenals (E21). B, Fluorescence microscopy of anti-chromogranin A (polyclonal, red), anti-GDNF (monoclonal, green), and its double detection (yellow) of bovine chromaffin cells after 6 d in culture.