However, the ultimate objective is to produce essential, ultra-rare blood types that are difficult to get. People who require regular blood transfusions for illnesses such as sickle cell anaemia must have these.
If the blood is not an exact match, the body rejects it, and the treatment is unsuccessful. This level of tissue matching exceeds the commonly known A, B, AB, and O blood types.
Prof Ashley Toye of the University of Bristol stated that certain groupings were "very, extremely rare" and that "perhaps just ten persons in the country" could donate.
There are now only three units of the Indian-discovered "Bombay" blood group in store in the entire United Kingdom.