Abstract: Objective To explore the method of induction of pancreatic stem cells into islet-like structures, and to perform the relate measurements. To investigate the techniques and methods to differentiate the pancreas stem cells into the islet-like structure as well as the detection method. Methods Through amplifying pancreas stem cells in the same culture bottle to obtain enough pancreas stem cells. To observe the morphological changes of pancreas stem cells after nicotinamide induction. The cell clusters were preformed with morphological observation, dithizone dyeing, Mallory dyeing and immunohistochemistry staining. Result The pancreas stem cells were in colony distribution, with single big nuclear, refraction shining brilliantly, morphology was stable, nestin and AKP were both positive. After induction, the pancreatic stem cells gathered together and formed cell clusters, packed with intact membrane. The cells in the structures were positive with DTZ staining. With FITC tagging the insulin antibodies, the cells towards the center of the structures were insulin-producing cells of green fluorescence. While after Mallory staining , the structures were dressed into two different colour, in the centre of the cell cluster were faint yellow, periphery of cell cluster were red, the staining of the cell cluster was similar to the natural islets after Mallory staining. Conclusion Pancreatic stem cells could directional be induced into islet-like structures in vitro under appropriate conditions.

Key words: pancreatic stem cells, cultivation in vitro, directional induction, islet-like structures