Use of density perturbation to isolate immunologically distinct populations of cells

Experiments have been carried out to demonstrate that, using antibody coated-Dynabeads as a model system for density labelling MOLT-4 T cells, the overall density of cells can be increased such that the cells that bind particles can be separated on isopycnic density gradients from cells that bind fewer particles. The increase in density is dependent on the cell volume and the number of particles bound. After centrifugation, cells with bound particles were found at positions in the gradient that reflected their increased density. Observed density ranges for cells with particular numbers of particles bound coincided closely with calculated expected density ranges. These results indicate the potential for separation of different subpopulations of cells on the basis of the immunological identity of the surface of cells using density perturbation methods involving antibody coated-density particles.