Azuzul drops demonic blood in Sam which mutates Sam. Physiologically,when ingested,the gi tract degrades and absorbs product. Blood of any kind would naturally be degraded. Implications are that red blood cells are the responsible component for the mutation. Red blood cells have no nucleus and thus no DNA and cannot cause mutations. The spinal cord is responsible for producing all blood cells. Is it possible that Sam was changed by a demonic virus that was absorbed and alters his natural cellular production? I have too much time on my hands and this point is minute; as a physician it disturbs me. There may be a feeling amongst the production team that some of us need a reality check and I suspect this applies to me. I am impressed with your work. Please do not kill off Bobby and Castiel forever.

Superfan