DNA storage of hair. Clipping or pulling?

[Futuregenetics]

Hi, I want to storage DNA in hair for at least 5 years. Does it affect the sample if I clip the hairstraws out with a scissor instead of pulling them out? According to the article in the link below one should pull the hair out:  https://www.google.no/amp/s/m.wikihow.com/Collect-DNA%3famp=1 Thank you for reply. 

[CharonY]

Hair does not contain living cells. You need hair roots in order to isolate DNA.

[Futuregenetics]

14 hours ago, CharonY said:

Hair does not contain living cells. You need hair roots in order to isolate DNA.

Thank you for reply, are you sure about this?

[mistermack]

11 minutes ago, Futuregenetics said:

Thank you for reply, are you sure about this?

Hair contains one form of dna, but it's mitochondrial dna, which only gives limited information. The roots contain nuclear dna as well, which is the one that is wanted for identification purposes. A friend of mine had a dna test done recently for paternity purposes, and it was done by just taking swabs from the inner cheek.

If you want to store it for five years, I would say, get a commercial kit, then get full hair samples, with the root, or cheek swabs, and put them quickly in a good freezer that runs at minus 20 C. You would be better off getting lots of dna material, because it gradually degrades over time, especially if it's warmed to room temperature. 

[StringJunky]

Quote

To ensure high quality microarray results, we recommend the following DNA storage strategies:

Short-term storage (weeks) at 4°C in Tris-EDTA
Medium-term storage (months) at –80°C in Tris-EDTA
Long-term storage (years) at as –80°C as a precipitate under ethanol
Long-terms storage (decades) at –164°C or dried

Read more>> https://www.ogt.com/resources/literature/403_dna_storage_and_quality

 

[mistermack]

Another strategy might be to throw your sample in a glacier for five thousand years. 

Ötzi the ice mummy had intact dna, they were even able to determine that he was lactose intolerant. And there was meat in his stomach that was dna tested as Ibex meat.    

[Strange]

3 minutes ago, mistermack said:

Another strategy might be to throw your sample in a glacier for five thousand years. 

That assumes that glaciers will be around for another 5000 years, which is looking increasingly unlikely. 

[StringJunky]

47 minutes ago, Strange said:

That assumes that glaciers will be around for another 5000 years, which is looking increasingly unlikely. 

Yes ,the glaciers are revealing new bodies, of mountaineers and skiers quite frequently now with them melting. George Mallory's body, who died climbing Everest in 1924 was discovered last year.

[mistermack]

They found Mallory about 20 years ago. I don't think they've ever found Irvine's body. I don't think Mallory was in a glacier, and if he was, it I doubt if it would be much affected by warming at 8,000 m. But it's actually in the nature of glaciers that they will eventually spit out their contents, warming or no warming. But glaciers certainly are retreating, there's no doubt about that.  

[StringJunky]

17 minutes ago, mistermack said:

They found Mallory about 20 years ago. I don't think they've ever found Irvine's body. I don't think Mallory was in a glacier, and if he was, it I doubt if it would be much affected by warming at 8,000 m. But it's actually in the nature of glaciers that they will eventually spit out their contents, warming or no warming. But glaciers certainly are retreating, there's no doubt about that.  

Yes, I stand corrected.

[CharonY]

On 10/9/2018 at 4:22 AM, mistermack said:

Hair contains one form of dna, but it's mitochondrial dna, which only gives limited information.

That is not quite correct and probably requires that I qualify my previous statement. First, mitochondria are obviously present in cells, meaning that if you do not have nuclear DNA you also won't have mitochondrial DNA. However, you have more copies of the small mitchondrial genome in a given cell than nuclear DNA.

Here is where my qualifying statement comes in. Cells found in hair shafts are dead and thus DNA is heavily degraded, if at all present. However, due to the abundance of mitcohondria, there is a better change to scavenge enough mitochondrial DNA out of hair samples to get e.g. a PCR going.