A common way to quickly determine a person's blood type is based on agglutination. Blood from a patient is mixed with antibodies that were pre-spotted on a specific test card called Eldon card (Figure 1). This card contains specific antibodies against antigens A (Anti-A) and B (Anti-B) as well against the Rhesus (Rh) factor antigen D (Anti-D). On every card there is a fourth area that is left empty and used as a control to make sure that the experiment kit worked correctly.
Figure 1: Example of an Eldon Card.
If the tested blood contains the corresponding antigen to the specific antibody in the cycle, blood clots will be formed. Go to blood typing results to see all possible results of the blood typing test.