What is the universal blood donor type?

3 mins read

January is National Blood Donor Month, which makes this a good time to learn more about blood types

There are four blood types: A, B, AB and O, each differentiated by specific proteins called “antigens.” And blood also is classified by the rhesus, or Rh, factor — negative or positive.

Ideally, blood transfusions are performed with donated blood that’s an exact match for type and Rh factor. But what happens in an emergency, when there isn’t time or opportunity to check?

For emergency transfusions, blood group type O negative blood is the variety of blood that has the lowest risk of causing serious reactions for most people who receive it. Because of this, it’s sometimes called the universal blood donor type.

Blood group types are based on proteins called antigens that are present on red blood cells. There are major antigens and minor antigens coating the red blood cells. Based on the major antigens, blood groups may be classified as one of these four types:

Type A

Type B

Type AB

Type O

Blood is also classified by rhesus (Rh) factor. If your blood has the Rh factor, you’re Rh positive. If your blood lacks the Rh factor, you’re Rh negative.

Ideally, blood transfusions are done with donated blood that’s an exact match for type and Rh factor. Even then, small samples of the recipient’s and donor’s blood are mixed to check compatibility in a process known as crossmatching.

In an emergency, type O negative red blood cells may be given to anyone — especially if the situation is life-threatening or the matching blood type is in short supply.

Contributing writer: Rajiv K. Pruthi, M.B.B.S.


Is it safe for me to donate blood during the coronavirus outbreak?

In healthcare settings across the United States, donated blood is a lifesaving, essential part of caring for patients. The need for donated blood is constant, and blood centers are open and in urgent need of donations. People who are well are encouraged to continue to donate blood if they are able, even if they are practicing social distancing because of COVID-19. The CDC is supporting blood centers by providing recommendations that will keep donors and staff safe. Examples of these recommendations include spacing donor chairs 6 feet apart, thoroughly adhering to environmental cleaning practices, and encouraging donors to make donation appointments ahead of time.


One Blood Lowcountry Donation Center 1001-A Boundary St.Beaufort, SC 29902Phone: 843-522-0409

American Red Cross Palmetto Service Center181 Industrial Park Rd.Hardeeville, SC 29927Phone: 843-757-7437

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