What is the purpose of blood cross-matching?

The purpose of blood cross-matching is to mix the recipient's blood with the donor's blood to check for agglutination. This process is crucial before a transfusion because it helps ensure compatibility between the two blood types. When incompatible blood types mix, antibodies in the recipient's blood can react with proteins on the donor red blood cells, leading to agglutination, which can cause serious complications such as hemolysis, organ failure, or even death.

In a transfusion, the goal is to provide blood components that the recipient's immune system will accept without mounting an adverse response. Cross-matching is a key safety step that determines if the blood will cooperate effectively, preventing harmful reactions. The other options listed pertain to different medical assessments that do not relate to blood transfusion compatibility.