Scientists are working to grow the rarest blood type in the world in a lab, an effort that could have huge ramifications for medicine. The blood type in question, Rh null, is found in just 50 people ...

* Rh-null blood lacks all 61 Rh antigens, making it extremely rare and medically valuable * It can save lives as a universal donor within rare blood types * Rh-null individuals //can only receive ...