Irish Blood Transfusion Service Service. The frequency of blood groups in Ireland is as follows: It is important that the IBTS collects enough O Rh D positive blood as almost half the population are that blood type. Donors with O Rh D negative are known as universal donors. Their blood can be transfused to patients of any other blood group in an emergency or if the patient's own blood group is unavailable. Because any patient can receive O Rh D negative blood, the IBTS need to have extra O Rh D negative blood available at all times. The service depends entirely on voluntary donations
ABO blood group system The resulting red blood cells do not usually express A or B antigen at the same level that would be expected on common group A or B red blood cells, which can help solve the problem of an apparently genetically impossible blood group. The table above summarizes the various blood groups that children may inherit from their parents. Genotypes are shown in the second column and in small print for the offspring: AO and AA both test as type A; BO and BB test as type B. The four possibilities represent the combinations obtained when one allele is taken from