Final answer:
Agglutination tests with anti-A, anti-B, and anti-Rh sera determine a patient's blood type; blood agglutinating with anti-B serum suggests a B-type, and a cross-match assay ensures transfusion compatibility. If agglutination occurs with both anti-A and anti-B, the blood type is AB; if there's no agglutination, the type is O-negative.
Step-by-step explanation:
Determining Blood Type Through Agglutination Tests
Agglutination tests using anti-A, anti-B, and anti-Rh sera are instrumental in determining ABO blood types and Rh factor for transfusions and other medical purposes. When a patient's blood agglutinates with anti-B serum, it indicates that B antigens are present on the surface of the red blood cells, meaning the patient's blood type could be B-positive or B-negative. To clarify, it's crucial to test the blood with anti-Rh serum to determine the presence of the Rh factor. A cross-match assay is then performed to ensure compatibility between donor and recipient. This involves mixing a small sample of the donor's red blood cells with the recipient's serum to check for hemagglutination.
If both anti-A and anti-B antibodies cause agglutination, the blood type is AB. If no agglutination occurs in any of these tests, the blood type is O-negative, indicating an absence of A, B, and Rh antigens. Abnormal reactions, such as a lack of expected agglutination or agglutination in all samples, may suggest potential errors or the presence of additional antibodies, which would require further investigation.