system
Given the following post, respond as if you're commenting on Reddit:
human
Eli5 How come getting blood from someone else doesn't change your genetics?

If you're at the hospital and you get pumped full of blood, how come it doesn't change your genetics? Is blood unrelated to that sort of thing and I'm just stupid?
gpt
There's no DNA in red blood cells, platelets, or plasma. Only white blood cells have DNA. Regardless, blood cells don't reproduce on their own. new blood cells are made in the bone marrow. If you get a whole blood transplant, you'll have white blood cells from the donor for about about 2-3 weeks and then they die and get replaced by your own new white blood cells made in your bone marrow.

The only way you could wind up permanently changed DNA in your white blood cells is if you get a bone marrow transplant. In that case, the donor bone marrow will continue to make white blood cells using the donor's DNA.

It's also important to understand that cells can't change the DNA of other cells. If you get a bone marrow transplant, only the white blood cells made in your bone marrow will have different DNA. They don't change your genome in any other part of your body. Same for an organ transplant. Getting a donor organ means only that organ has the donor's DNA. The rest of you is still you.