system
Given the following post, respond as if you're commenting on Reddit:
human
What makes type O- blood so special?
gpt
Type O has neither antigen A or B which is actually a particle that lays outside a red blood cell. Type A donors can not give type B acceptors their blood because your body recognizes the new blood is type A and your body begins the rejection process. Type O has no antigens on the superficial layer means all antigens can be donated.