Immunocytochemistry of Pancreatic Beta Cells

Immunocytochemistry was performed using standard methods^{4 (link), 41 (link)}. Briefly, islets were dispersed, transduced, and plated on cover slips. Insulin (DAKO, Carpinteria, CA) and Ki67 (Fisher Scientific) primary antisera were used to immunolabel beta cells entering the cell cycle. A tissue microarray containing formalin-fixed, paraffin-embedded tissue sections of Insulinoma and normal pancreas tissue from the same and different clinical cases were generated by the Biorepository and Pathology CORE at the Icahn School of Medicine at Mount Sinai. Primary antisera against p57 (Cell Signaling, Danvers, MA) and Insulin (DAKO, Carpinteria, CA) were used to label p57 in human beta cells. Secondary antisera were from Invitrogen (Carlsbad, CA). Confocal fluorescent microscopy was performed using an Olympus Fluoview 1000 microscope.