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Blood compatibility checker.
Who can donate to whom? Select the patient's blood group and the component needed, the answer changes for red cells vs plasma.
The rules in one breath
Red cells
O− gives to everyone (universal red-cell donor). AB+ receives from everyone (universal red-cell recipient). Otherwise: the patient's Rh sign must match or be negative, and the patient's letter must accept the donor's letter.
Plasma, the mirror image
AB is the universal plasma donor. O receives plasma from everyone. That is why plasma compatibility reads like red-cell compatibility reversed.
Need a real donor in Assam?
Need a donor with a matching group? Post a request and every matching voluntary donor near the patient gets alerted, free. Or register as a donor yourself on the two-minute form.
The two rules behind all of it
Red cells: the donor's ABO and Rh must be compatible with the patient, O− fits everyone, AB+ accepts everyone. Plasma: the opposite, AB plasma fits everyone. That single inversion is the whole table above.
Why this matters in an emergency
No time to crossmatch? The hospital gives O− red cells. That is why O− donors are gold, only about 2 in 100 Indians are O−. And when a patient's group is unknown, "Any" on the request form alerts every donor nearby.
Full group-by-group detail: blood groups explained · rare groups · red cells vs plasma compatibility.
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