1. Determining Your Blood Type
A, B, AB or O?

2. The ABO Blood Group System
There are four major blood groups determined by the presence or absence of two antigens – A and B – on the surface of red blood cells: Antigen: An antigen is any substance that causes the immune system to produce antibodies against it.

3. Antigens explained:
Group A – has only the A antigen on red cells (and B antibody in the plasma)
Group B – has only the B antigen on red cells (and A antibody in the plasma)
Group AB – has both A and B antigens on red cells (but neither A nor B antibody in the plasma)
Group O – has neither A nor B antigens on red cells (but both A and B antibody are in the plasma)

4. Antigens explained:
In addition to the A and B antigens, there is a third antigen called the Rh factor, which can be either present (+) or absent ( – ). In general, Rh negative blood is given to Rh-negative patients, and Rh positive blood or Rh negative blood may be given to Rh positive patients.
The universal red cell donor has Type O negative blood type.
The universal plasma donor has Type AB positive blood type

5. Antigens and Antibodies:

6. Blood Types and the Population
O positive is the most common blood type. Not all ethnic groups have the same mix of these blood types. Hispanic people, for example, have a relatively high number of O’s, while Asian people have a relatively high number of B’s.

7. How Is My Blood Type Determined?
It’s inherited. Like eye color, blood type is passed genetically from your parents. Whether your blood group is type A, B, AB or O is based on the blood types of your mother and father.

8. Who’s your daddy?

9. How Is My Blood Type Determined?
Genotype (DNA) Blood Type: AO or AA: A blood type AB: AB blood type BO or BB: B blood type OO: O blood type One is from your father and one from your mother.

10. Phenotypes and Genotypes:

11. Co-dominance:

12. How do I test my blood?
Dispense one drop of your blood to each field on the test card. Use the toothpick provided. The fields contain antibodies, which will provoke a reaction with antigens on your red blood cells.
Use a new toothpick for each field to mix the blood with the antibodies, creating about a dime-sized smear.

13. Eldon cards:

14. Results?
If you have blood type A, clumping will appear in following fields: anti-A
If you have blood type B, clumping will appear in the field: anti-B
If you have blood type AB, clumping will appear in fields anti-A, anti-B
If you have blood type O, no clumping will appear
Rh+ will clump, Rh- will not