The present invention provides a homogeneous assay for identifying an antibody producing cell producing an antibody which binds to a selected antigen comprising: a) providing a population of antibody producing cells; b) incubating said population of antibody producing cells with a selected antigen and a labeled anti-antibody antibody, wherein said anti-antibody antibody is capable of distinguishing cells producing an antibody which binds to the selected antigen from those cells which do not; and c) identifying an antibody producing cell capable of producing an antibody which binds to the selected antigen.