A person with type O− blood can receive a blood donation from which blood types?

A person with type O− blood has no A antigens, no B antigens, and no D (Rh) antigen on their red blood cells. Because they lack all three of these surface markers, their immune system has produced both anti-A and anti-B antibodies, and they are capable of producing anti-D antibodies if ever exposed to Rh-positive blood. This means an O− recipient will have an immediate hemolytic transfusion reaction if given A, B, or AB blood because the pre-formed antibodies will attack the donor cells. They will also develop sensitization — and potentially a hemolytic reaction on subsequent exposure — if given Rh-positive blood. Therefore, the only safe donation for an O− individual is O− blood, which also lacks A, B, and D antigens. O+ would trigger an Rh response, A− would trigger an anti-A reaction, and AB− would trigger both anti-A and anti-B reactions, making all three distractors incorrect. The answer O− only is correct, confirming the keyed response. This concept is tested frequently because O− donors are the universal donors, but O− recipients are the most restricted in what they can accept — a common exam misconception to watch for.