Patients can safely receive blood from donors with compatible blood types. For example, people with type A blood can only receive type A or type O blood, while people with type AB blood can receive all blood types. However, If incompatible blood is given in a transfusion, the patient's immune system will attack the donor cells, which can cause shock, kidney failure, circulatory collapse, and death.
Therefore, all bloods must be tested for compatibility rate for everyone's safety.
Time went past.. Raven straightened his back when the doctor returns. A news of being perfectly match to Dwight's sent him to unimaginable happiness. During the time of blood testing, Raven prayed a lot. He doesn't care if Xavier might possibly killed him, as long as Dwight is safe.
"Mr. Salvador, please wait here, we'll have to prepare you take some of your blood. Don't worry, we have everything prepared for your fast recovery." The doctor said with a genuine smile on her face.