摘要 |
An isolated and purified glycoprotein and functional analogues thereof are disclosed. The glycoproteins are characterized by being expressed on at least primitive hematopoietic cells, and being a ligand for L-selectin. The binding activity of the ligand of the present invention to L-selectin is not sulfation-dependent and it is neither inhibited by anti-CD34 antibodies nor by MECA-79 monoclonal antibody and the ligand is resistant to O-sialoglycoprotein endopeptidase activity. Further, the present invention provides a method of performing an overlay adherence assay by using isolated cells or cell lines as a substrate. The cells are prepared as the substrate for the assay using a cytocentrifuge with a modified sample chamber allowing placement of the cytocentrifuged cell pellet to any selected location on the slide as required by the shear conditions employed for any given assay.
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