This document provides guidance on using an antibody identification (ABID) panel to rule out potential alloantibodies in a patient's serum. The summary is: 1. Reactions on the ABID panel indicate different reaction strengths, suggesting multiple antibodies or different antibody dosages. The patient's auto control is negative. 2. To rule out antigens, only use panel cells with no reaction. Mark out antigens on each cell until one antigen remains. 3. After ruling out on all cells, if one antigen meets the "Rule of Three" and matches the reaction pattern, it cannot be ruled out yet. Phenotype the patient's cells for that antigen to determine the antibody. 4