For blood transfusions, it is crucial to determine the donor's and recipient's blood group because otherwise the matching antibodies in the recipient's serum could bind to the donor's foreign antigens. That leads to life-threatening clumping of the blood cells which could block the blood vessels. Another type of transfer from donor to recipient is transplantation. In medicine, the movement of organic material is referred to as transplantation. We will find out more about blood transfusion and organ transplantation in this film.