Direct hemagglutination of Rh(D)-positive RBCs by mRh1. (A) Incubation of papain-treated Rh(D)-positive RBCs with DF5 MoAb (positive control). (B) Incubation of papain-treated Rh(D)-negative RBCs with mRh1. (C) Incubation of papain-treated Rh(D)-positive RBCs with mRh1. (D) Incubation of papain-treated Rh(D)-negative RBCs with culture medium (negative control). Agglutinated RBCs remained at the top of the columns.