Blood Types

Each person has a specific blood type, based on the combination of factors included in their blood. This blood type allows medical facilities to give the right blood to the right patient, as well as helping blood centers find the best donation for your type.

Blood type is one of the most referenced part of blood donation, but do you know what it means? Your blood type is determined by which antigens are present in your blood. Antigens and the blood type they give us show us which blood is the best fit for the patient and will be best tolerated after transfusion

The letter in your blood type – A, B or O – is decided by the ABO antigen. Blood from O donors can be given to any other blood type, while A, B or AB donors’ blood can only be given to those who share that type.

The positive or negative after your blood type is determined by the Rh antigen. Blood from negative-type donors can be given to anyone sharing their ABO type, making O-negative donors the universal donor whose blood can safely be given to anyone.

Use the chart below to see who your blood can be given to.

An infographic explaining blood type compatibility

Your blood contains hundreds of other antigens, the combination of which can make some people’s blood quite unique. Our laboratories work every day to help match blood from our donors to the unique and specialized needs of patients across the nation.

Learn More About Our Laboratories

What is a RARE Donor? Why do I have a purple tag on my unit?

A rare donor is a blood donor that has been identified as being negative for certain red cell antigens. There are more than 600 red cell antigens which includes the antigens that determines your blood type, the ABO and Rh antigens. If your blood type is found in 1 in 1000 people, you are considered a rare donor. When a donor is found to be a rare donor, a purple tag is affixed to the red blood cell unit and used for transfusion to a patient who needs rare blood.