Determination of immunoglobulin classes of specific antibodies secreted by single cells. A cluster formation assay.

A method is described to identify specific antibody-forming cells and their immunoglobulin classes by a multilayer cluster formation. Cells producing specific antibodies are mixed with erythrocytes coated with the corresponding antigen in presence of rabbit anti-human immunoglobulins. Clusters are formed only if the mixtures contain rabbit antiserum against the immunoglobulin chains of the specific secreted antibody. Thus the immunoglobulin class of the specific antibody is assessed. For this study the cells of three EBV-transformed, antibody-producing human lymphoblastoid cell lines were used.