EVERYONE HAS a blood group, outlined by the attribute chains of sugar molecules, or antigens, that protrude from their crimson blood cells like spikes on a hedgehog’s again. Not all these teams are created equal. Within the roughly 50% of individuals with kind O, the sugars are innocent, permitting their blood to be transfused into any needy physique. In these with A and B blood teams, nonetheless, the antigens can set off dangerous immune reactions in somebody with a special group. These with AB blood, who’ve each varieties of antigen, can solely donate blood to 1 one other.
