Separation of rare cell subpopulations with the aid of biotin-labelled ligands.

A universal method for selection of surface marker-positive cells is described. The cells, admixed with an excess of surface marker-negative cells, are first labelled with a specific biotinylated ligand and then isolated with the aid of monoclonal, anti-biotin coated beads. The method enables selection and isolation of cells with a frequency as low as 10(-4). The ligand can be an antigen (for selection of infrequent antibody-producing cells), an antibody (for selection of surface antigen-positive cells) or other molecules (for selection of specific receptor-positive cells).