This Protein A ELISA is intended for detection of natural and recombinant Protein A in Bioprocess manufacturing applications. There are occasions where Protein A or its fragments leach from a puriffcation column and remain bound to the Fc region of a therapeutic antibody. This must be avoided in order to preclude any adverse effects of Protein A on the patient, particularly in instances where antibodies are manufactured for pharmaceutical uses. This ELISA can be utilized as a Protein A ligand leaching quality control step in the mAb development workffow.