Electrophoretic mobility and N-acetyl neuraminic acid content of human normal and leukemic lymphocytes and granulocytes.

T HE SURFACE CHARGE OF MAMMALIAN CELLS is considered to be one of several factors determining the balance between attractive and repulsive forces that operate between the cell periphery and other surfaces of potential contact.1’2 The surface-charge density of the leukocyte may be important in determining surface characteristics such as adhesiveness, deformability, and pseudopod formation. Variations in the latter characteristics are likely to be of major importance in determining the ability of leukocytes to remain in or leave the bone marrow, to marginate and exit from the vascular compartment, and to ingest particulate material. Human leukocytes, like other mammalian cells examined, carry a net negative surface charge at physiologic pH.3 Furthermore, it has been shown that the negative charge of leukocytes can be reduced by the action of the enzyme, neuraminidase (n-acetyl neuraminidate glycohydrolase)4; hence, a portion of the surface charge is considered to be due to ionized carboxyl group of