Lymphoid cell fractionation on magnetic polyacrylamide-agarose beads

This paper describes a new method of fractionation of mouse and rat lymphoid cells using as an insoluble support polyacrylamide-agarose spherical beads in which iron oxide particles were trapped (Magnogel) and coated with purified anti-mouse or anti-rat Ig antibodies. The advantage of this method is that both non-adsorbed and adsorbed cells are easily and rapidly recovered due to the magnetic properties of the beads. The viability of the fractionated cells is unaffected and total recovery is high: between 80 and 100%. Surface immunoglobulin-bearing cells and cells containing immunoglobulins in their cytoplasm were searched in the various fractions. 99.6–99.9% of the cells not retained on anti-Ig coated Magnogel were devoid of surface immunoglobulins and were composed of small T lymphocytes and of some immunoglobulin-containing plasma cells. In this fraction, the depletion of the surface Ig-positive cells is of 117–400-fold. The cells adsorbed on the beads were recovered by mechanical stirring followed by the application of a magnet to separate the beads and the cells. The latter were composed of surface Ig-bearing B lymphocytes (62–79%) which were enriched 1.7–2.1-fold, surface Ig-negative cells (21–38%) and some immunoglobulin-containing cells.