Abstract: The cell observation using a conventional well plate takes much costs. Each well 3 being opened at a top plate 2a of the well plate 1 has a diameter reduced portion 32 which inner circumferential surface 32a is conically hollowed. At a lower portion of the diameter reduced portion 32 is formed an inserting hole 33. In a detecting portion 4, an outer circumferential surface of a round-bar reference electrode 41 is covered by an insulating portion 42. The detecting portion 4 has an upper end portion 4a and a lower end portion 4b which outer circumferential surface is exposed to an outside without being covered by an insulating portion 42. On an upper side above the lower end portion 4b is formed a diameter expanded portion 4c in which an outer circumferential surface of the insulating portion 42 is covered with a measuring electrode 43. The detecting portion 4 is fixed to a well 3 whose diameter expanded portion 4c is inserted into an inserting hole 33 and its upper end portion 4a is contained in the well 3.

Abstract: The cell observation using a conventional well plate takes much costs. Each well 3 being opened at a top plate 2a of the well plate 1 has a diameter reduced portion 32 which inner circumferential surface 32a is conically hollowed. At a lower portion of the diameter reduced portion 32 is formed an inserting hole 33. In a detecting portion 4, an outer circumferential surface of a round-bar reference electrode 41 is covered by an insulating portion 42. The detecting portion 4 has an upper end portion 4a and a lower end portion 4b which outer circumferential surface is exposed to an outside without being covered by an insulating portion 42. On an upper side above the lower end portion 4b is formed a diameter expanded portion 4c in which an outer circumferential surface of the insulating portion 42 is covered with a measuring electrode 43. The detecting portion 4 is fixed to a well 3 whose diameter expanded portion 4c is inserted into an inserting hole 33 and its upper end portion 4a is contained in the well 3.

Abstract: The present invention provides clonal pluripotent hepatic stem cells using flow cytometry and in vitro single-cell-based assays. These cells possess multilineage differentiation potential and self-renewing capability. These cells may be clonally propagated in culture, to continuously produce hepatocytes and cholangiocytes as descendants while maintaining primitive stem cells. When expanded cells are transplanted into recipient animals, they morphologically and functionally differentiated into hepatocytes and cholangiocytes, with reconstitution of hepatocyte and bile duct structures. Furthermore, these cells differentiated into pancreatic ductal and acinar cells or intestinal epithelial cells when transplanted into pancreas or duodenal wall. Thus, the self-renewing multipotent stem cells persist in the developing mouse liver and can be induced to become cells of other organs of endodermal origin under appropriate microenvironment, providing new insight into therapies for diseases of the digestive system.