Development of a protein A enzyme immunoassay for use in screening hybridomas.

A protein A enzyme immunoassay has been developed which is effective in the rapid screening of hybridomas. The detecting reagent is a stable alkaline phosphatase-protein A conjugate, prepared by a simple, inexpensive, single-step procedure. The assay requires small amounts of antigen to coat microtiter wells (less than 25 microgram/well) and can be evaluated visually or with a spectrophotometer. It compares favorably in sensitivity to a protein A-radioimmunoassay and enjoys considerably lower backgrounds than that popular screening procedure.