How do we determine which blood groups a person can donate to? If a person has the A blood type, she carries antigens for A. She can donate to people with blood type A and AB. This is because people with either the A blood type or the AB blood type are used to “seeing” the A antigen floating around and therefore will not mount a response to the A blood type. A trick for remembering this is to make a chart similar to the one I drew below. Draw a line connecting the A blood type to any blood types that have A listed in the antigen column. Now you can list those blood types in the third column as the blood types for which A blood can be donated to.
The same is true for B blood. People that have the B blood type carry the B antigen. People with either B or AB blood are used to seeing the B antigen floating around and therefore would not mount a response to B blood. Therefore blood type B can be donated to people that have B and AB blood. Try my trick again. Draw lines connecting B blood type in the first column to any B antigens in the second column. Those are the people that B blood can be donated to.
Now we get to AB blood. AB blood carries both the A and B antigen. Only people that are used to seeing both the A and B antigen present would be okay with receiving AB blood. People with AB blood can only donate to people with AB blood. Using my trick, draw a line to any antigen that contains both A and B. It’s only one blood type, AB.
Finally we reach O blood. O carries no antigens. So it wont harm anyone. O can be donated to any of the four blood types. Of course we are just looking at one type of antigen on red blood cells. There are hundreds. For a perfect match, you have to perform a bloodtyping test.
Articles to be posted in the future will focus on receiving blood and the rhesus factor. Remember to “Like” this website on Facebook (see upper right hand corner) to be updated on future posts. Thanks!