# Can forensics match DNA in poop? **URL:** \ **Category:** Factual Questions\ **Created:** [July 26, 2022, 11:39pm UTC](https://boards.straightdope.com/t/can-forensics-match-dna-in-poop/968626 "2022-07-26T23:39:52Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Peter\_Morris](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/peter_morris/32/359_2.png) [@Peter\_Morris](https://boards.straightdope.com/u/Peter_Morris)\ **Post date:** [July 26, 2022, 11:39pm UTC](https://boards.straightdope.com/t/can-forensics-match-dna-in-poop/968626/1 "2022-07-26T23:39:52Z")
A point raised in another thread > [@Is there video of how order was restored on January 6, 2021?](https://boards.straightdope.com/t/is-there-video-of-how-order-was-restored-on-january-6-2021/968523/3): > > What I’d like to know is something gross. I understand some of the J6 rioters pooped in the Capitol. Was the poop ever analyzed for DNA? It would be great if the poopers could be named and shamed. Is that even possible? I suspect it would be quite a challenge. AIUI, poop consists largely of: 1. broken and discarded red blood cells 2. dead intestinal bacteria 3. undigested remnants of food. The red blood cells don’t contain DNA, so can’t be matched. Am I correct on that? And there’s no point in analyzing the bacteria and cellulose. I suppose the intestine might shed some cells occasionally, which could provide DNA to match, but how difficult is it to isolate them in a pile of poop? ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [July 27, 2022, 12:17am UTC](https://boards.straightdope.com/t/can-forensics-match-dna-in-poop/968626/2 "2022-07-27T00:17:26Z")
Not only can you get DNA from poop, you can get DNA from old poop: > **[Paleofeces](https://en.wikipedia.org/wiki/Paleofeces)** > > Paleofeces (or palaeofaeces in British English) are ancient human feces, often found as part of archaeological excavations or surveys. The term coprolite is often used interchangeably, although coprolite can also refer to fossilized animal feces. Intact feces of ancient people may be found in caves in arid climates and in other locations with suitable preservation conditions. They are studied to determine the diet and health of the people who produced them through the analysis of seeds, small b... > The success rate of usable DNA extraction is relatively high in paleofeces, making it more reliable than skeletal DNA retrieval. ---
**Author:** ![md-2000](https://avatars.discourse-cdn.com/v4/letter/m/9d8465/32.png) [@md-2000](https://boards.straightdope.com/u/md-2000)\ **Post date:** [July 27, 2022, 1:01am UTC](https://boards.straightdope.com/t/can-forensics-match-dna-in-poop/968626/3 "2022-07-27T01:01:05Z")
I read about some place where they were using DNA analysis of dog feces to find people who did not clean up after their dog. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [July 27, 2022, 1:27am UTC](https://boards.straightdope.com/t/can-forensics-match-dna-in-poop/968626/4 "2022-07-27T01:27:48Z")
So random DNA found in samples of dog feces are matched to public and private databases so that those people can be found and then any dogs in their possession are tested to match the illegally abandoned feces? ---
**Author:** ![needscoffee](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/needscoffee/32/1076_2.png) [@needscoffee](https://boards.straightdope.com/u/needscoffee)\ **Post date:** [July 27, 2022, 1:36am UTC](https://boards.straightdope.com/t/can-forensics-match-dna-in-poop/968626/5 "2022-07-27T01:36:44Z")
> [@TriPolar](#): > > So random DNA found in samples of dog feces are matched to public and private databases so that those people can be found and then any dogs in their possession are tested to match the illegally abandoned feces? - I’ve read where condos/apartment buildings that have dog poop problems will make every dog owner submit a sample from their dog so they can ID the culprit. ---
**Author:** ![Jackmannii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackmannii/32/311_2.png) [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)\ **Post date:** [July 27, 2022, 1:47am UTC](https://boards.straightdope.com/t/can-forensics-match-dna-in-poop/968626/6 "2022-07-27T01:47:44Z")
And dog DNA from unwanted deposits could eventually be identified through investigation of canine genealogy sites. ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [July 27, 2022, 2:50am UTC](https://boards.straightdope.com/t/can-forensics-match-dna-in-poop/968626/7 "2022-07-27T02:50:13Z")
> [@Jackmannii](#): > > And dog DNA from unwanted deposits could eventually be identified through investigation of canine genealogy sites The future is weird. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [July 27, 2022, 2:53am UTC](https://boards.straightdope.com/t/can-forensics-match-dna-in-poop/968626/8 "2022-07-27T02:53:55Z")
> [@Darren\_Garrison](#): > > The future is weird. Well… > [@needscoffee](#): > > I’ve read where condos/apartment buildings that have dog poop problems will make every dog owner submit a sample from their dog so they can ID the culprit. …the present is no Shangri-La either. ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [July 27, 2022, 2:55am UTC](https://boards.straightdope.com/t/can-forensics-match-dna-in-poop/968626/9 "2022-07-27T02:55:19Z")
I meant now. This is the future. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [July 27, 2022, 4:26am UTC](https://boards.straightdope.com/t/can-forensics-match-dna-in-poop/968626/10 "2022-07-27T04:26:05Z")
Already? I just can’t keep up. ---
**Author:** ![Andy\_L](https://avatars.discourse-cdn.com/v4/letter/a/c67d28/32.png) [@Andy\_L](https://boards.straightdope.com/u/Andy_L)\ **Post date:** [July 27, 2022, 4:48am UTC](https://boards.straightdope.com/t/can-forensics-match-dna-in-poop/968626/11 "2022-07-27T04:48:50Z")
> [@Darren\_Garrison](#): > > The future is weird As Gibson said, the future’s poop is already here; it’s just not evenly distributed ---
**Author:** ![Francis\_Vaughan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/francis_vaughan/32/3093_2.png) [@Francis\_Vaughan](https://boards.straightdope.com/u/Francis_Vaughan)\ **Post date:** [July 27, 2022, 6:38am UTC](https://boards.straightdope.com/t/can-forensics-match-dna-in-poop/968626/12 "2022-07-27T06:38:36Z")
> [@Peter\_Morris](#): > > AIUI, poop consists largely of: > > 1. broken and discarded red blood cells > 2. dead intestinal bacteria > 3. undigested remnants of food. The intestine sheds epithelial cells from its lining. So much so that it is the cell line with the highest rate of reproduction in the body, renewing the lining about once a week. (And why you get severe gastrointestinal problems with radiation sickness, as the cell is vulnerable to radiation damage when the DNA strands are unraveled for duplication.) There will be a lot of useful DNA to be recovered. ---
**Author:** ![FinsToTheLeft](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/finstotheleft/32/2930_2.png) [@FinsToTheLeft](https://boards.straightdope.com/u/FinsToTheLeft)\ **Post date:** [July 27, 2022, 10:25am UTC](https://boards.straightdope.com/t/can-forensics-match-dna-in-poop/968626/13 "2022-07-27T10:25:37Z")
Cologuard detects cancer by finding altered DNA from cancerous cells from your colon in a tiny sample, so yes your DNA can be detected in your poop. ---
**Author:** ![md-2000](https://avatars.discourse-cdn.com/v4/letter/m/9d8465/32.png) [@md-2000](https://boards.straightdope.com/u/md-2000)\ **Post date:** [July 27, 2022, 10:50am UTC](https://boards.straightdope.com/t/can-forensics-match-dna-in-poop/968626/14 "2022-07-27T10:50:23Z")
> [@Darren\_Garrison](#): > > I meant now. This is the future. Muppet Labs - where the future is now. ---
**Author:** ![kayaker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kayaker/32/441_2.png) [@kayaker](https://boards.straightdope.com/u/kayaker)\ **Post date:** [July 27, 2022, 11:30am UTC](https://boards.straightdope.com/t/can-forensics-match-dna-in-poop/968626/15 "2022-07-27T11:30:15Z")
FREE BEER TOMORROW. 🍻 ---
**Author:** ![JKellyMap](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jkellymap/32/15880_2.png) [@JKellyMap](https://boards.straightdope.com/u/JKellyMap)\ **Post date:** [July 27, 2022, 12:03pm UTC](https://boards.straightdope.com/t/can-forensics-match-dna-in-poop/968626/16 "2022-07-27T12:03:27Z")
> [@Peter\_Morris](#): > > broken and discarded red blood cells I learned about this from a Straight Dope column, decades ago. The letter to Cecil was signed “Billy Rubin.” 🙂 ---
**Author:** ![Peter\_Morris](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/peter_morris/32/359_2.png) [@Peter\_Morris](https://boards.straightdope.com/u/Peter_Morris)\ **Post date:** [July 27, 2022, 1:16pm UTC](https://boards.straightdope.com/t/can-forensics-match-dna-in-poop/968626/17 "2022-07-27T13:16:20Z")
Was that before or after _The Silence of the Lambs_ (which used the same joke)? ---
**Author:** ![StarvingButStrong](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/starvingbutstrong/32/335_2.png) [@StarvingButStrong](https://boards.straightdope.com/u/StarvingButStrong)\ **Post date:** [July 27, 2022, 2:39pm UTC](https://boards.straightdope.com/t/can-forensics-match-dna-in-poop/968626/18 "2022-07-27T14:39:50Z")
So… If the sample comes from a cannibal, could you find enough DNA to identify his latest meal? ---
**Author:** ![Anaglyph](https://avatars.discourse-cdn.com/v4/letter/a/ed8c4c/32.png) [@Anaglyph](https://boards.straightdope.com/u/Anaglyph)\ **Post date:** [July 27, 2022, 5:58pm UTC](https://boards.straightdope.com/t/can-forensics-match-dna-in-poop/968626/19 "2022-07-27T17:58:54Z")
This is a science news review from 20 years ago “The first evidence of human tissue in prehistoric human waste dating back about 850 years shows that people of southwestern Colorado engaged in cannibalism during a long drought, according to a new study” > **[Study Provides Direct Evidence Of Cannibalism In The Southwest](https://www.sciencedaily.com/releases/2000/09/000913204822.htm)** > > The first evidence of human tissue in prehistoric human waste dating back about 850 years shows that people of southwestern Colorado engaged in cannibalism during a long drought, according to a new study. and a recent article: " The what, how and why of archaeological coprolite analysis" > **[The what, how and why of archaeological coprolite analysis](https://www.sciencedirect.com/science/article/pii/S0012825220302427)** > > Coprolites are a highly informative but still underutilized proxy for understanding past environments, palaeodiets, and ancient human health. Here we … ---
**Author:** ![StarvingButStrong](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/starvingbutstrong/32/335_2.png) [@StarvingButStrong](https://boards.straightdope.com/u/StarvingButStrong)\ **Post date:** [July 27, 2022, 6:20pm UTC](https://boards.straightdope.com/t/can-forensics-match-dna-in-poop/968626/20 "2022-07-27T18:20:21Z")
> [@Anaglyph](#): > > This is a science news review from 20 years ago Just when you think you’ve asked a completely silly question… Still. Okay, they can ID that the meat was human flesh. But is the dna in that meat still in good enough shape to be able to match it college student who disappeared hitchhiking a couple days ago? [Next page](https://boards.straightdope.com/t/can-forensics-match-dna-in-poop/968626.md?page=2)