Partial Separation of Human Blood Leukocytes by Density Gradient Electrophoresis: Different Mobilities of Lymphocytes with IgG, Those with IgM and IgD, T Lymphocytes, and Monocytes

Previous studies on the electrophoretic separability of human T and B peripheral lymphocytes have produced conflicting results. Vassar et al. (1) using the microscope chamber technique were unable to show any correlation between electrophoretic mobility and degree of enrichment in either T or B lymphocytes. In contrast to the above results, other laboratories (2–6) have shown charge differences between human T and B cells of such magnitude that suggest the possibility of complete separability of these two populations. However, the microscope chamber method does not provide actual physical separation of the electrophoresed cells. Recent attempts by Stein (7) and Häyry et al. (8) to separate physically T and B human lymphocytes by free flow electrophoresis resulted only in partial enrichment of these cells in certain fractions. In consideration of the above findings and in view of the importance of separating human lymphocyte subpopulations by physical methods, we have applied the recently developed technique of density gradient electrophoresis (9, 10), to examine the separability of these cells. Our results suggest that complete resolution of T and B cells as such is not achieved, but that the surface IgM- and IgD-bearing cells are significantly enriched in the slow mobility fractions. In addition, enrichment of monocytes in the high mobility fraction was observed.