Evaluation of monoclonal anti-A reagents by salivary inhibition studies

Ten commercially available monoclonal and polyclonal anti-A reagents were evaluated for use in the test for ABH secretor status after finding unexpected inhibition with a monoclonal anti-A (reagent Z). Two of the available monoclonal reagents were from different batches from the same clone as reagent Z. Those two reagents, as well as reagent Z, appeared to be partially neutralized by salivary substances from group A nonsecretor individuals. This finding suggests that when a saliva inhibition test is done, a nonsecretor control saliva of the same ABO group as the saliva to he tested should be used.