The results of testing RoHarr cells with panels of monoclonal anti-D suggest that the D antigen (referred to as DHar) encoded by the haplotype (D)c(e) Rh33 is a partial D antigen. IgM monoclonal anti-D are more efficient than IgG monoclonal anti-D in detecting DHar.DHar expresses some but not all of both epD5 and epD6/7 and appears to lack epD1-epD4, epD8 and epD9.