Antibodies eluted from kidneys by traditional methods of pH shift have been used as reagents in a wide variety of experimental analyses without knowledge of whether their ligand affinity influenced their removal from parenchymal tissue. In the current study we employed two monoclonal antibodies, differing only in their functional affinity (high; K = 2.1 x 10(8)/M and low; K = 6.2 x 10(6)/M) to a common ligand found on the renal basement membrane, to evaluate whether a standard elution technique might selectively facilitate the removal of one antibody over the other. Our findings indicate, however, that the routine methods of elution by pH shift remove both antibodies equally well (41-48%), and without loss of paratypic function. These results provide new evidence that elution by pH shift can produce eluate antibodies which are not biased by preferred affinities.