We are not a blood bank. We connect people who need blood with people who can give it.

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Assam Blood Donor
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O−

The O− blood group.

well under 1 in 30 of people in India, a rare group.

The universal donor: every patient can take O− red cells, but only O− donors can give to O− patients. The group every blood bank runs short of first.

Register as a O− donor Can I donate?

0 active O− donors on the Assam register right now · Need O− blood? start a request →

O− can donate to

O+O−A+A−B+B−AB+AB−

O− can receive from

O+O−A+A−B+B−AB+AB−
How this works in real hospitals.Compatibility above is for red cells, simplified. In practice the blood centre runs a crossmatch before every transfusion, and plasma/platelet rules differ. Final decisions always belong to the treating centre, never self-arrange a match.

O− is rare, the register needs you specifically.

Register once; we contact you only when a compatible patient near you needs blood.

Register as a O− donor
Who can O− blood be given to?

O− red cells can go to patients with: O−, O+, A−, A+, B−, B+, AB−, AB+. Compatibility is decided by the blood centre's crossmatch, never self-match.

Who can donate to an O− patient?

O− patients can receive red cells from: O−.

Is O− a rare blood group?

O− is rare in India, well under 1 in 30 of the population. Rare-group patients depend heavily on voluntary registers like ours.