Final answer:
Type and cross match is the process used to ensure compatible blood types between a blood donor and recipient by testing for reactions between donor antigens and recipient antibodies.
Step-by-step explanation:
Checking blood samples from both donor and recipient to ensure the greatest compatibility is called Type and cross match. This process includes two main steps: typing the blood to determine the ABO and Rh blood types, and then cross-matching to ensure the donor blood does not have any antigens that would react with antibodies in the recipient's serum. During a type and cross match, possible reactions are observed through the use of anti-A, anti-B, and anti-D antibodies. These tests are crucial for preventing transfusion reactions which may be life-threatening.