With kind assistance from: focus-AF Limited, Privatklinikgruppe Hirslanden, Klinikum Bielefeld

Blood is the human body's elixir. There are various blood groups which are differentiated according to certain features of the red blood cells and a number of proteins in the blood. Antigens, which ensure that antibodies are formed as soon as they are considered to be foreign by the organism, are found on the surface of the red blood cells. They are always present in certain combinations in humans. And those combinations are what define the different blood groups. The most important blood group systems are the AB0 system and the Rhesus system. We will find out more about these two systems in this film.