Antigens of the Rh system belong to the clinically most important antigens of the erythrocyte membra- ne. They play an important role in haemolytic disease of the newborn, posttransfusion reactions and autoimmune haemolytic anaemia. Serological detection of these antigens is based on the reaction of the appropriate antigen and specific anti-Rh antibody. The development of diagnosis developed from original polyclonal complete sera to highly specific and intensely reacting monoclonal antibodies. Correct antigen detection of antigens may be complicated by falsely positive and falsely negative results. Complications associated with detection and interpretation of results are caused also by weak and variant forms of antigen RhD.

        Key words: Rh system, Rh antigens, serological diagnosis, polyclonal and monoclonal antibodies, falsely positive and falsely negative reactions, weak and variant forms of RhD