AIM:To localize nestin positive cells (NPC) in pancreatic tissue of mice of different ages. METHODS: Paraffin sections of 6-8 μm of fixed pancreatic samples were mounted on poly-L-lysine coated slides and used for Immunolocalization using appropriate primary antibodies (Nestin, Insulin, Glucagon), followed by addition of a fluorescently labeled secondary antibody. The antigen-antibody localization was captured using a confocal microscope (Leica SP 5 series). RESULTS: In 3-6 d pups, the NPC were localized towards the periphery of the endocrine portion, as evident from immunolocalization of insulin and glucagon, while NPC were absent in the acinar portion. At 2 wk, NPC were localized in both the exocrine and endocrine portions. Interestingly, in 4-wk-old mice NPC were seen only in the endocrine portion, towards the periphery, and were colocalised with the glucagon positive cells. In the pancreas of 8-wk-old mice, the NPC were predominantly localized in the central region of the islet clusters, where immunostaining for insulin was at a maximum. CONCLUSION: We report for the first time theimmunolocalization of NPC in the pancreas of mice of different ages (3d to 8wk) with reference to insulin and glucagon positive cells. The heterogeneous localization of the NPC observed may be of functional and developmental significance and suggest(s) that mice pancreatic tissue can be a potential source of progenitor cells. NPC from the pancreas can be isolated, proliferated and programmed to differentiate into insulin secreting cells under the appropriate microenvironment. METHODS: Paraffin sections of 6-8 μm of fixed pancreatic samples were mounted on poly-L-lysine coated slides and used for Immunolocalization using primary primary antibodies (Nestin, Insulin, Glucagon) followed by addition of a fluorescently labeled secondary antibody. The antigen-antibody localization was captured using a confocal microscope (Leica SP 5 series). RESULTS: In 3-6 d pups, the NPC were localized towards the periphery of the endocrine portion, as evident from immunolocalization of insulin and glucagon, while NPC were absent in the acinar portion. At 2 wk, NPC were localized in both the exocrine and endocrine portions. Interestingly, in 4-wk-old mice NPC were seen only in the endocrine portion, towards the periphery, and were colocalized with the glucagon positive cells. In the pancreas of 8-wk-old mice, the NPC were predominantly localized in the central region of the islet cl usters, where immunostaining for insulin was at a maximum. CONCLUSION: We report for the first time theimmunolocalization of NPC in the pancreas of mice of different ages (3d to 8wk) with reference to insulin and glucagon positive cells. The heterogeneous localization of the NPC observed may be of functional and developmental significance and suggest (s) that mice pancreatic tissue can be a potential source of progenitor cells. NPC from the pancreas can be isolated, proliferated and programmed to differentiate into insulin secreting cells under the appropriate microenvironment.