DNA and Poo

[Fuzz]

Bit of an odd subject I know but...

The farm got done over a few weeks back by those caravan dwellers.
Now we found where the vehicle drove down the farm tracks and identified where they parked up. Also there was some human poo (unless an animal has evolved to wipe itself with tissue paper) :D
Now we got soco in to dust down the vanss that were also done, however they said they couldn't get DNA from poo !! (might get some skin cells from the tissue paper though)

Nearly every website I look at on the web says the opposite.
What the hells going on?
Are they telling the truth here, or just reluctant go poking around in it!

:confused:

[fatboyjim154]

You can retrieve Mitochondrial DNA from poopie as I found out a while ago.

Jim

[wazza]

I think that I heard on an FLO course where we do body retreval from major accidents and searching for DNA to ID that body that poo was not one of places to find any. I may be mistaken but thats what i think i was told

[fatboyjim154]

http://www.springerlink.com/content/h2248801714k5316/

Nice little report about it all.

[Meridian]

That paper is 1995, and DNA technology moves fast. Mitochondrial DNA is no longer used for faeces because the probabilities are too long, and it just says "a member of this family". The FSS now uses LCN techniques on faeces samples to get a full profile, and I assume the private wallahs do as well. But... LCN is very expensive (thousands of pounds per sample) and very prone to contamination. With a sample like that, out in the open, the defence might easily claim contamination with wind-born DNA. Yes it can be done. Whether anyone will pay for it is a different question. Especially if the first attempt fails and further tests, at two thousand pounds plus a time, are required.


M

[VinnyP!]

The paper is the best bet. Expect tissue (Pun intended) and even blood. LCN is very expensive throughout the chain as collection, storage continuity and court presentation are 10s of times more difficult and costly and it is far less conclusive because of the contimination problems. It's use was suspended for a while but has now been re-instated but only in very serious cases.

[Talon]

Id be amazed if you could get a clear DNA sample from faeces. Being a large proportion dead gut flora would hihgly confuse any techniques.

[SteveScooby]

I was told by one of our SOCOs recently that you can't get DNA fron it

[7db]

If I eat someone, presumably their DNA is in my poo.

[jamesson]

That's a nice thought, Hannibal.

[Hoon Devil]

So you could eat them, then get them blamed for a crime by leaving their DNA at the scene, so to speak?


Lovely.

[Meridian]

I was told by one of our SOCOs recently that you can't get DNA fron it



Your SOCO is wrong. Either your SOCO isn't keeping up, or he/she has been told to deter people from asking for it due to the excessive cost.


M

[Meridian]

Id be amazed if you could get a clear DNA sample from faeces. Being a large proportion dead gut flora would hihgly confuse any techniques.



The DNA technique used is very specific, and the area targeted is only found in the human genome. Any other non-human DNA would just show up as random noise. At least that's my understanding. Otherwise most DNA testing would be a problem due to microbes in the air landing on the stains under examination.


M

[7db]

So you could eat them, then get them blamed for a crime by leaving their DNA at the scene, so to speak?


Lovely.


Well yes, unless the crime in question was the eating of them. They can't be guilty of that.