snopes.com Post new topic  Post a reply
search | faq | forum home

  next oldest topic   next newest topic
» Hello snopes.com » Archived Forums » Crime Archive » Blood transfusion changes DNA?

 - UBBFriend: Email this page to someone!    
Author Topic: Blood transfusion changes DNA?
Mike67
The Red and the Green Stamps


Icon 1 posted            Edit/Delete post   Reply with quote 
Did a Google search and didn't really find anything on this one. Just curious...if someone gets a blood transfusion then takes a DNA test, will the results show DNA from the other person? Would make an intersting plot to a crime novel.
IP: Logged | Report this post to a moderator
diddy
Markdown, the Herald Angels Sing


Icon 1 posted      Profile for diddy   E-mail diddy   Send new private message       Edit/Delete post   Reply with quote 
I doubt it considering how much normal blood a person has in their bodies...

--------------------
W.W.F.S.M.D?
But this image of Bush as some sort of Snidely Whiplash tying the fair maiden to the railroad tracks is beyond the pale. - Joe Bentley

Posts: 2311 | From: Minnnesota | Registered: Mar 2004  |  IP: Logged | Report this post to a moderator
Rychan
The Red and the Green Stamps


Icon 1 posted            Edit/Delete post   Reply with quote 
I don't know how the tests actually work, but I would hope that at worst, both sets of DNA would manifest themselves.

reminds me of the people who have multiple sets of DNA (lotsof us?)

http://arbl.cvmbs.colostate.edu/hbooks/genetics/medgen/chromo/mosaics.html

IP: Logged | Report this post to a moderator
Slainey
Little Sales Drummer Boy


Icon 1 posted      Profile for Slainey   E-mail Slainey       Edit/Delete post   Reply with quote 
A relative who had a bone marrow transplant delighted in telling folks that he now has a different blood type. Not really what you are asking.

I'd think that the donated blood would be diluted pretty quickly. The odds of finding the non native cells seems remote. Why does this seem like something med students would try to figure out?

I read about genetic Chimeras a few years ago in the Journal Science and was pretty tickled to see it come up on a recent rerun of CSI.

Posts: 2655 | From: MO USA | Registered: Jul 2003  |  IP: Logged | Report this post to a moderator
smilodonna
The Red and the Green Stamps


Icon 1 posted            Edit/Delete post   Reply with quote 
I think that any nucleated blood cells don't stick around very long after a transfusion, so chances would probably be very slim that donor DNA would show up on a blood test. Not to mention that any nucleated cells would be greatly diluted by the recipient's blood volume.

Most blood cells, of course, are red blood cells which do not contain nuclei.

IP: Logged | Report this post to a moderator
Casey, making hot chocolate
Let There Be PCs on Earth


Icon 1 posted      Profile for Casey, making hot chocolate   Author's Homepage   E-mail Casey, making hot chocolate   Send new private message       Edit/Delete post   Reply with quote 
Blood tends to only remain in the body a month or so before being degraded, but if the person had a DNA test right after a transfusion, I see no reason why not.

--------------------
"To be or not to be! That is the question! Now, will you answer, dare, double dare, or take the Physical Challenge?" --Mark Summers as Hamlet
Countdown: 177 days and counting... or less. My blog. 14 keyboards owed.

Posts: 5584 | From: Ohio | Registered: Dec 2003  |  IP: Logged | Report this post to a moderator
Joseph Z
Xboxing Day


Icon 1 posted      Profile for Joseph Z   E-mail Joseph Z   Send new private message       Edit/Delete post   Reply with quote 
Watch James Bond's last movie with Halle Berry at the DNA lab. He explains the identity change routine.

He says they replace DNA, Bone Marrow, and I think he said other things that change your identity.

Matching people's identity is a tricky business. Most coroners use dental work for positive matches if the face and prints are not recognizable before resorting to dna and bone marrow testing to find a match.

----------

However, some do use dna testing to find the suspect or victim if blood is found in an unknown situation like a gunshot hit a fleeing suspect that got away. They can use that blood within a matter of hours to find out who it was long as he didn't change himself in that way.

--------------------
Joseph Z

Posts: 1356 | From: Woodbridge, VA | Registered: Jul 2004  |  IP: Logged | Report this post to a moderator
Oualawouzou
Angels Wii Have Heard on High


Icon 1 posted      Profile for Oualawouzou     Send new private message       Edit/Delete post   Reply with quote 
Correct me if I'm wrong, but I don't think a single cell is used to determine someone's DNA. As soon as the "alien" blood would mingle with the patient's "real" blood, any sample would overwhelmingly carry the patient's "real" DNA, unless it's an extreme case where massive transfusions are necessary...

Keep in mind I have no medical experience other than fainting while giving blood though. [Razz]

--------------------
Le champignon arrive.

Posts: 4372 | From: Quebec | Registered: Apr 2003  |  IP: Logged | Report this post to a moderator
Dogwater
Happy Holly Days


Icon 1 posted      Profile for Dogwater   E-mail Dogwater   Send new private message       Edit/Delete post   Reply with quote 
As Slainey made reference to, here's Uncle Cecil's take on it.

--------------------
As God is my witness, I thought turkeys could fly.

Posts: 1679 | From: Illinois | Registered: Jul 2004  |  IP: Logged | Report this post to a moderator
GI Joe
Jingle Bell Hock


Icon 1 posted      Profile for GI Joe     Send new private message       Edit/Delete post   Reply with quote 
I'm no expert, but when I've seen people have DNA sample taken, they used an oral swab to collect salivia. I assumed - yes, dangerous - that oral swabs were the normal method of DNA typing for living type folks. If that's the case, someone else's blood flowing in your veins would not really matter would it?

--------------------
Once a Warrior Prince

Posts: 496 | From: California | Registered: Apr 2002  |  IP: Logged | Report this post to a moderator
WildaBeast
Let There Be PCs on Earth


Icon 1 posted      Profile for WildaBeast   E-mail WildaBeast   Send new private message       Edit/Delete post   Reply with quote 
I remember a fairly recent episide of one of the Law & Order shows where the suspect had had a bone marrow transplant, and therefore his blood had different DNA from the rest of him. Thus when the detectives did a DNA test it didn't match the blood at the crime scene, even though it was later found to be his blood.

quote:
I'm no expert, but when I've seen people have DNA sample taken, they used an oral swab to collect salivia.
I'm pretty sure they're collecting cells from the inside of the cheek, not just saliva. Can you get DNA just from saliva?

--------------------
"Unseasonable is an odd word to begin with. It sounds like it's describing something that it's impossible to sprinkle pepper on." -- Nonny

Posts: 5483 | From: Just south of Folsom Prison, CA | Registered: Jul 2002  |  IP: Logged | Report this post to a moderator
medtchva
Deck the Malls


Icon 1 posted      Profile for medtchva   E-mail medtchva   Send new private message       Edit/Delete post   Reply with quote 
quote:
Originally posted by Casey, talking to the Godfather:
Blood tends to only remain in the body a month or so before being degraded, but if the person had a DNA test right after a transfusion, I see no reason why not.

Actually, red blood cells live for an average of 120 days. Platelets (clotting cells) live 7 to 10 days. White blood cells live 2-3 weeks.
Posts: 229 | From: Lynchburg, VA | Registered: Jan 2005  |  IP: Logged | Report this post to a moderator
medtchva
Deck the Malls


Icon 1 posted      Profile for medtchva   E-mail medtchva   Send new private message       Edit/Delete post   Reply with quote 
quote:
Originally posted by WildaBeast:
quote:
I'm no expert, but when I've seen people have DNA sample taken, they used an oral swab to collect salivia.
I'm pretty sure they're collecting cells from the inside of the cheek, not just saliva. Can you get DNA just from saliva? [/QB]
Yes you are right - they collect cells from the cheek (called a buccal swab) for DNA analysis. But it can be done on any cells from the body - buccal cells, blood, skin, semen & vaginal samples, etc.

There was a crime show that had a doctor who was raping women and a blood sample was taken for DNA. The results didn't match. Later a new victim positively IDed the doctor, and a new blood sample drawn, and it still didn't match. Turned out the doctor had implanted a tube under his skin like a vein and before the sample were drawn, he'd fill the tube with someone else's blood. Best fake example of screwing with a DNA sample I've seen.

As for bone marrow - before a person receives a bone marrow transplant, radiation is used to kill all of the person's bone marrow. The donor bone marrow is injected into the blood stream and the new cells will take hold in the empty bone marrow space and begin producing blood cells. So yes, it is possible for a bone marrow recepient to have different DNA patterns between their blood and other body cells.

Posts: 229 | From: Lynchburg, VA | Registered: Jan 2005  |  IP: Logged | Report this post to a moderator
the Virgin Marrya
Let There Be PCs on Earth


Icon 1 posted      Profile for the Virgin Marrya     Send new private message       Edit/Delete post   Reply with quote 
FWIW, when our baby daughter 'needed' a DNA test, I have no idea why they didn't swab inside her cheek.

It takes a lot of squeezing to get a couple of decent drops of blood out of a baby fingerprick

--------------------
Windows cannot open this file. To open this file correctly, defenestrate, then try running the file again...

Posts: 5383 | From: New Zealand | Registered: Jan 2003  |  IP: Logged | Report this post to a moderator
medtchva
Deck the Malls


Icon 1 posted      Profile for medtchva   E-mail medtchva   Send new private message       Edit/Delete post   Reply with quote 
quote:
Originally posted by Marrya tyler more please...:
FWIW, when our baby daughter 'needed' a DNA test, I have no idea why they didn't swab inside her cheek.


It could be one of a couple of reasons. The hospital almost certainly sends DNA samples to a reference lab for testing - that lab may not use saliva as a sample. Saliva is more easily contaminated than a tube of blood. Saliva also degrades faster than blood.
Posts: 229 | From: Lynchburg, VA | Registered: Jan 2005  |  IP: Logged | Report this post to a moderator
RoofingGuy
The First USA Noel


Icon 1 posted      Profile for RoofingGuy     Send new private message       Edit/Delete post   Reply with quote 
quote:
Originally posted by WildaBeast:
Can you get DNA just from saliva?

Well, like most things, yes and no...

As mentioned, the buccal swab is intended to collect skin cells from the inside of the cheek.

From LabCorp:
quote:
Buccal Swabs - the New Specimen of Choice for DNA Testing


Buccal swabs are rapidly becoming the specimen of choice for DNA testing. The specimen is collected by gently stroking the inner facial cheek with swabs similar to cotton tipped applicator sticks.

The buccal cells:

-do not require refrigeration or preservatives
-do not need immediate shipping to the laboratory
-remain usable even after years of storage

Buccal swab specimens are not affected by:

-toothpaste
-chewing tobacco or other tobacco products
-lipstick
-foods
-bacterial DNA (bacteria do not contain the DNA sequences examined in the test)

No fasting is required prior to specimen collection and LabCorp has experienced no appreciable need to re-collect of buccal swab specimens.

The HLA testing performed on these specimens is performed using state-of-the-art DNA methods, the same DNA tests used on blood specimens. These techniques offer significantly improved accuracy over conventional HLA typing methods (serology).

But, although the fluid "saliva" itself is essentially without nucleic cells, there are often buccal cells in samples of saliva such as found on cigarette butts, or drinking glasses, etc... so that saliva can be used in some cases for running DNA testing.
Posts: 724 | From: Ontario, CAN | Registered: Jan 2005  |  IP: Logged | Report this post to a moderator
Vivling
Happy Holly Days


Icon 1 posted      Profile for Vivling     Send new private message       Edit/Delete post   Reply with quote 
quote:
Originally posted by medtchva:
There was a crime show that had a doctor who was raping women and a blood sample was taken for DNA. The results didn't match. Later a new victim positively IDed the doctor, and a new blood sample drawn, and it still didn't match. Turned out the doctor had implanted a tube under his skin like a vein and before the sample were drawn, he'd fill the tube with someone else's blood. Best fake example of screwing with a DNA sample I've seen.

Ooo I saw that, too. I think it was L&O. He got what he deserved, though-- (warning minor spoiler for Tivo folks) the blood that he said was his own was actually taken from a man responsible for an unsolved child molestation case.

--------------------
Climb up, over the the top
Shake it, take control
You've got to find out for yourself whether or not you're truly trying
--Jason Mraz

Posts: 1686 | From: British Columbia | Registered: Jul 2003  |  IP: Logged | Report this post to a moderator
medtchva
Deck the Malls


Icon 1 posted      Profile for medtchva   E-mail medtchva   Send new private message       Edit/Delete post   Reply with quote 
Yes I'm pretty sure it was Law & Order... was one of the best ones I ever saw.
Posts: 229 | From: Lynchburg, VA | Registered: Jan 2005  |  IP: Logged | Report this post to a moderator
   

Quick Reply
Message:

HTML is not enabled.
UBB Code™ is enabled.

Instant Graemlins
   


Post new topic  Post a reply Close topic   Feature Topic   Move Topic   Delete topic next oldest topic   next newest topic
 - Printer-friendly view of this topic
Hop To:


Urban Legends Reference Pages

Powered by Infopop Corporation
UBB.classic™ 6.7.2