“…In contrast, neomycin, chloramphenicol, and gentamicin do not seem to bond covalently to RBC membranes and are easily washed away. The reports of ABO grouping problems due to these antibiotics [3][4][5][6][7] suggest that the in vitro reactions parallel those described for the drugs reacting by the so-called "immune complex" mechanism. 2,8,9 That is to say, the reactions are seen only when the patient's serum, containing the antibody, is added to RBCs in the presence of the antibiotic (i.e., in the commercial RBC suspension medium).…”