Use of antibody-coated polyacrylic plastic beads for semiquantitative determination of cell surface antigens

Polyacrylic plastic beads coated with specific antibodies, which had previously been shown to bind specifically to cells carrying the related antigen, are shown to react quantitatively with the antigen on individual cells. The number of beads per cell which can be counted by simple microscopy is a measure of the amount of antigen accessible on the cell surface. The method may also be used in combination with other methods for cell surface antigens, such as immunofluorescence, for multiple antigen determination.