Blood group O has no A or B antigens on red blood cells but contains both anti-A and anti-B antibodies in the plasma. Individuals with this blood group can donate red blood cells to anyone (universal donor), but can only receive blood from group O. Blood group O is the most common blood type in many populations. Due to the absence of A and B antigens, it is crucial for emergency transfusions.
Your red blood cells do not have A and B antigens, and your plasma contains antibodies against both A and B antigens.
To all blood groups: A, B, AB, and O.
Only individuals with blood group O.