Science question!

[_testify_]

If someone had a significant amount of blood transfusions, say due to an accident or somesuch, and then within a few days cut themselves...is there any chance the spilled blood could test positive for the DONOR'S DNA and not the receipient's?

At what point does their blood become your own?

[rug]

1. Er . . . what do you have in your freezer?

[_testify_]

2. It's a legitimate question!

I was wondering, is all...


Freezer's clean. Now, if you'd asked about the trunk of my car...

[giant_robot]

3. Interesting question!

The two major cellular components of blood are erythrocytes (red blood cells) and leukocytes (white blood cells). Most blood cells are erythrocytes (about 98%, if I recall correctly), which contain neither a nucleus nor DNA. So, even if donor erythrocytes were spilled, no identification could be made by DNA fingerprinting.

As to what happens to donor leukocytes, I'm not really sure. ABO typing doesn't apply to leukocytes, so they'd probably be identified as "foreign" by the host's immune system and destroyed by phagocytes, probably within 24 hours or so. I'd say it would have to take some really unusual circumstances in order for one to bleed donor leukocytes, and even if you did, you would bleed some of your own leukocytes as well, so a DNA fingerprint would yield two unique DNA profiles.

As to your question, "When does your blood become your own?", I'd have to say that is becomes your own once the donor RBCs are replaced by your own. Erythrocyte lifespan is about 3 months, iirc, so I'd say it takes about 3 months after a transfusion before your blood is totally your own.

[_testify_]

4. Well done!

Thank you for explaining that.

:yourock:

[giant_robot]

5. Your welcome!

I'm glad that 8 years of graduate school is good for something! LOL!