The limited supply of reagent human polyclonal antibodies to high prevalence antigens, like Jsb, is driving the search for alternative reagents. Murine immunoglobulin G (IgG) monoclonal antibodies (Mabs) and their humanized chimaeric IgM isoforms can now be used for typing patients and screening donors. Antigen typing of red blood cells (RBC) with a positive direct antiglobulin test (DAT) is also possible using these antibodies. Blood from patients with sickle cell disease and African donors were tested with reagent anti-Jsb, murine Mab IgG anti-Jsb [murine immunochemistry monoclonal antibody-8 (MIMA-8)], and humanized chimaeric IgM anti-Jsb [human immunochemistry monoclonal antibody-8 (HIMA-8)] by haemagglutination and gel cards. RBC samples that were DAT positive were used to evaluate the humanized chimaeric IgM monoclonal anti-Fya (HIMA-19). RBC samples (n = 243) of known Jsb type were tested in parallel with MIMA-8 and reagent anti-Jsb, and 132 samples were tested with MIMA-8 in gel cards and HIMA-8 by direct tube testing. No discrepant results were obtained. DAT-positive RBC samples (n = 27) were correctly phenotyped using HIMA-19. We conclude that MIMA-8 is suitable for screening donors and typing patient RBCs. Testing MIMA-8 with gel cards containing anti-mouse IgG enables the screening of donors by automated methods. Humanized chimaeric IgM anti-Jsb and anti-Fya are suitable as typing reagents by direct agglutination methods.