Cross-matching of blood samples is done in cases when multiple blood transfusions are being done in order to try and prevent transfusion reactions from happening. Blood from the donor and blood from the recipient is mixed together in different ways to see if the red blood cells move away from each other and agglutinate or if they remain together and show that they do not react with each other; if there is no reaction, we have a better chance of no transfusion reaction happening whilst the patient is receiving the blood transfusion.
