The monoclonal antibody 34-3C recognizes an exposed surface determinant of intact red blood cells (RBC). The high-affinity anti-RBC monoclonal antibody efficiently bind to Fc receptors on macrophages inducing anemia in vivo due to a rapid Fc receptor (FcyR)-mediated erythrophagocytosis of opsonised RBC in spleen and livers. The capacity of the antibody to interact with FcyR is responsible for its haemolytic activity. The monoclonal antibody only recognises antigenic determinants expressed on Mouse RBC and not on other species of RBC.