Detection of regulatory receptors and distinctive surface markers.

Cell sorting has been used as an approach to describing surface markers and functional receptors of hemopoietic stem cells and progenitors. Significant enrichment of CFU-S was obtained with fluorescent cell sorting of human antihuman sperm-labelled bone marrow cells; significant enrichment of human CFU-C was obtained by cell sorting of hybridoma (KGP1)-labelled human bone marrow cells. Significant changes in human bone marrow CFU-C, but not CFU-E were observed by fluorescence polarization after exposure to a putative stimulator of CFU-C. A description of preliminary investigations of a hybrid clone from Dexter culture cells x Chinese hamster ovary and fluorescence polarization measurements after exposure to purified mouse-lung CSF are also presented.