Figure 8.

Double immunofluorescence staining of the islet-associated protein (IA-2) family of protein tyrosine phosphatases (PTPs) with glucagon in rat duodenum. Sections were reacted with anti–IA-2 (A–C) or anti–IA-2β (D–F) antibodies in combination with anti-glucagon antibody. Arrowheads indicate doubly immunolabeled gastrointestinal endocrine cells (GECs). Negative control sections were stained with a mixture of anti-rabbit/anti–guinea pig secondary antibodies without primary antibodies (G–I). Blue fluorescence indicates nuclear counterstaining. Bars, 20 µm.