Question

Samples of blood have been placed in each of the three depressions along with the appropriate antibody (anti-A, anti-B, and anti-Rh). (Dark dots indicate clumping, blank circles indicate no clumping.)



What is this person’s blood type?
O-

Answer 1

To determine a person’s blood type using the agglutination (clumping) test with anti-A, anti-B, and anti-Rh antibodies, we need to look at the reaction of the blood sample with each of these antibodies.

1. **Anti-A**: If agglutination occurs, it indicates the presence of A antigens (type A blood). If there is no clumping, A antigens are not present.

2. **Anti-B**: If agglutination occurs, it indicates the presence of B antigens (type B blood). If there is no clumping, B antigens are not present.

3. **Anti-Rh**: If agglutination occurs, it indicates the presence of Rh factor (Rh+). If there is no clumping, the person is Rh negative (Rh-).

Since you mentioned that the person has blood type O-, we can infer the following:

- **Anti-A**: No clumping (indicates type O).
- **Anti-B**: No clumping (indicates type O).
- **Anti-Rh**: No clumping (indicates Rh negative).

Therefore, the observations you provided support the conclusion that the person is indeed blood type O- (O negative).