Electrophoretic mobility properties of murine hemopoietic cells in different stages of development.

: In vivo spleen colony forming cells (CFUs) and three developmental stages of in vitro granulocyte/macrophage colony forming cells (GM CFUc 1, 2 & 3) are characterized by their surface charge density using the free-flow electrophoresis technique. CFUs have a somewhat higher electrophoretic mobility than have GM CFUc. GM CFUc 1, 2 & 3 appear to be identical in their mobility properties. Treatment with neuraminidase-by which negatively charged N-acetylneuraminic acid (NANA or sialic acid) groups are cleaved from membrane glycoproteins-changes the electrophoretic mobility of the various hemopoietic cells differentially. Neuraminidase treatment strongly reduces the electrophoretic mobility of CFUs and GM CFUc 1, has a moderate effect on the mobility of GM CFUc 2 and causes a relatively small reduction in the mobility of GM CFUc 3. It is suggested that the number of neuraminidase susceptible NANA groups on the cell surface decreases during early hemopoietic cell development.