Worrying about matching blood types may soon be a thing of the past now that scientists have developed a revolutionary technique for making a "universal" blood type.

Three-quarters of the world's population have one of four different kinds of blood types: A, B, AB, or O. The first three blood types each carry different strains of antigens and antibodies on the surface of their blood cells which provoke different immune responses. Since certain type A blood cells provoke immune responses against type B blood cells, we have thus far been unable to mix incompatible blood types for operations and treatments without the patient suffering a dangerous autoimmune reaction.

The O blood type, on the other hand, is considered the "universal" blood type because it only contains neutral antigens that can safely interact with the antigens of other blood types.