An IgG, gentamicin sulfate-dependent antibody found during prenatal antibody screening.

The serum of a prenatal patient was found to contain an IgG antibody that reacted with all red cells suspended in solutions containing the antibiotic gentamicin sulfate. The antibody was nonreactive with red cells suspended in media containing chloramphenicol, neomycin, hydrocortisone or inosine. Since gentamicin sulfate is used in the suspending medium of some commercial reagent red cell products, difficulties in the interpretation of antibody detection and identification tests may arise when patient sera contain gentamicin-dependent antibodies.