Store Human DNA for Decades: Room Temp, Blood Samples

  • Thread starter Jarfi
  • Start date
  • Tags
    Dna Human
In summary: In other words, after 521 years, less than 1% of the original amount of DNA would remain.So, DNA has a half-life of around 521 years and after that it will be almost completely degraded.
  • #1
Jarfi
384
12
How would I store human DNA for decades, at room temperature, blood samples and not too invasive methods available. It needs to be 100% undamaged and usable for genome mapping.
 
Biology news on Phys.org
  • #2
I believe for military purposes (identification of bodies) they store blood poured on some kind of (blotting) paper and dried out. There is a printed sheet with form to fill and two empty circles where the blood is poured on to dry. No idea if it is kept at room temperature nor what kind of paper they use, but there is no doubt they have the technology and it is rather simple.
 
  • #3
Borek said:
I believe for military purposes (identification of bodies) they store blood poured on some kind of (blotting) paper and dried out. There is a printed sheet with form to fill and two empty circles where the blood is poured on to dry. No idea if it is kept at room temperature nor what kind of paper they use, but there is no doubt they have the technology and it is rather simple.

I was rather thinking of a DIY method, not that I don't have paper I can drape in blood.
 
  • #4
What is not DIY about putting a drop of blood on the paper?
 
  • #5
Why would you want to do it?
 
  • #6
Borek said:
What is not DIY about putting a drop of blood on the paper?

It is suppost to last for decades, not years. I can do a DIY paper but I'm not sure if the blood in the paper will decompose into bacteria waste after decades.
 
  • #7
Ah, so it is good for military for bodies that are recovered after decades, but not good for you. OK, got it.
 
  • #8
Wikipedia has an article about the dried blood spot method that Borek mentioned:

http://en.wikipedia.org/wiki/Dried_blood_spot

And there is a section that explains why DNA remains stable at room temperature and while it sounds plausible, I couldn't find a reference for it:

The reason for stability of DNA, RNA or protein could be attributed to the fact that the biological material binds to the matrix of the filter paper and the process of drying excludes water which is an important factor necessary for protease or nuclease to act. Binding of the biological material also binds several inhibitors which may interfere with various nucleic acid amplification methods.

And here is an example of the method being employed in a practical setting:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC321659/

Dried blood spots (DBS) on filter paper facilitate the collection, transport, and storage of blood samples for laboratory use. A rapid and simple DNA extraction procedure from DBS was developed and evaluated for the diagnosis of human immunodeficiency virus type 1 (HIV-1) infection in children by an in-house nested-PCR assay on three genome regions and by the Amplicor HIV-1 DNA prototype assay version 1.5 (Roche Molecular Systems).

For these reasons, amplification of the integrated viral genome by PCR has been the preferred method for the diagnosis of HIV infection in children for many years (11). However, this method requires venipuncture in newborns for blood sampling and preparation of lymphocyte pellets, both of which are difficult to perform, particularly in developing country settings.

Dried blood spot (DBS) samples are an interesting alternative for lymphocyte pellets since only a few droplets of blood are required and can be directly collected on a filter paper. Storage and shipment of filter papers is easy since they can be kept at room temperature and DNA has a good stability in dried samples. Finally, DBS have been used for the detection of HIV-1 genome by PCR since 1991 (3-5) with good sensitivity and specificity.

They used PCR techniques to amplify the genetic material in the dried blood spot sample. In this case, they're testing for viral DNA but I believe the same also applies for human DNA.

Jarfi said:
It is suppost to last for decades, not years. I can do a DIY paper but I'm not sure if the blood in the paper will decompose into bacteria waste after decades.

Bacteria need water to grow and reproduce so it probably won't decompose into bacterial waste as long as the sample is completely dry. But DNA, while more stable than RNA, does still decompose over time so just out of interest, I looked into how long it takes for a strand of DNA to degrade and found this article:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3497090/

And here is a Nature article that removes all of the technical stuff and explains the important bits:

www.nature.com/news/dna-has-a-521-year-half-life-1.11555

By comparing the specimens' ages and degrees of DNA degradation, the researchers calculated that DNA has a half-life of 521 years. That means that after 521 years, half of the bonds between nucleotides in the backbone of a sample would have broken; after another 521 years half of the remaining bonds would have gone; and so on.

The team predicts that even in a bone at an ideal preservation temperature of −5 ºC, effectively every bond would be destroyed after a maximum of 6.8 million years. The DNA would cease to be readable much earlier — perhaps after roughly 1.5 million years, when the remaining strands would be too short to give meaningful information.

Since this DNA was collected from fossils that were probably in contact with groundwater at various points during fossilization and subjected to conditions that aren't exactly conducive for preservation, a DNA sample that is kept completely dry in ideal conditions should last much longer than this. Possibly even indefinitely since it is the reactions with water that are thought to be responsible for most bond degradation in the long run.
 
Last edited:
  • #9
Here's another article of interest:

http://www.ogt.co.uk/resources/literature/403_dna_storage_and_quality

Storage at –20°C to –80°C may well provide adequate conditions depending on the quality and quantity of DNA desired and the time frame in which the sample will be stored. However, neither of these conditions will maintain DNA quality equivalent to maintenance at liquid nitrogen temperatures over extended time periods (e.g. decades).

In contrast to storage of DNA in solution at very low temperatures, it is also possible to store DNA dried. This can be a practical alternative for long-term storage. In addition to reducing molecular mobility, dehydration also removes water that can participate in hydrolytic reactions. There are several methods of removing water from liquid preparations; these include spray drying, spray freeze drying, air drying or lyophilisation.

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

So basically you have two options if you want to store a DNA sample for decades. You could store it in liquid nitrogen or store it dried. Both techniques will keep the DNA relatively intact for decades. If you do decide to take the dried route, you could also slow down the rate of degradation even further and therefore maximize your chances of retrieving the DNA mostly intact by keeping the sample away from heat, sunlight, humidity, oxygen, etc.
 
Last edited:
  • Like
Likes 1 person
  • #10
boymilk said:
Here's another article of interest:

http://www.ogt.co.uk/resources/literature/403_dna_storage_and_qualitySo basically you have two options if you want to store a DNA sample for decades. You could store it in liquid nitrogen or store it dried. Both techniques will keep the DNA relatively intact for decades. If you do decide to take the dried route, you could also slow down the rate of degradation even further and therefore maximize your chances of retrieving the DNA mostly intact by keeping the sample away from heat, sunlight, humidity, oxygen, etc.
Excellent and professional! you have my thanks.
 
  • #11
Monique said:
Why would you want to do it?

Legal purposes.
 
  • #12
Jarfi said:
Legal purposes.

Are you sure you need to map the whole genome? Rather than trying to sequence everything, it would make far more sense, economically speaking, to only look at specific parts of the genome (e.g. known SNPs or VNTRs) if your goal is to use the DNA to identify individuals and/or gain information about their health.

On the other hand, the cost of whole genome sequencing is decreasing every year so maybe if you are willing to wait another decade or two for the prices to become affordable, then perhaps the above won't really matter by then.
 
Last edited:
  • #13
Jarfi said:
Legal purposes.

If you could provide more detailed information then members will be better able to help you. It may turn out you don't even need to store DNA for years at room temperature to achieve your goal, whatever it is.
 

1. How is it possible to store human DNA at room temperature for decades?

It is possible to store human DNA at room temperature for decades by using a preservative called EDTA (ethylenediaminetetraacetic acid). This chemical prevents the breakdown of DNA by binding to metal ions that can cause degradation. Additionally, DNA can also be stored in a dry state, preventing the growth of bacteria and fungi that can damage the DNA.

2. Can any type of blood sample be used for long-term DNA storage?

Yes, any type of blood sample can be used for long-term DNA storage as long as the DNA is extracted and preserved properly. Whole blood, plasma, serum, and dried blood spots can all be used for DNA storage. However, it is important to note that different types of blood samples may have different storage requirements and may require different preservation methods.

3. What is the advantage of storing human DNA at room temperature instead of freezing it?

Storing human DNA at room temperature has several advantages compared to freezing it. Firstly, it is more cost-effective as it eliminates the need for expensive refrigeration equipment and electricity costs. It also reduces the risk of sample degradation due to power outages or equipment failure. Additionally, room temperature storage allows for easier transport and sharing of DNA samples.

4. How can the quality of DNA be preserved when stored at room temperature for decades?

The quality of DNA can be preserved when stored at room temperature for decades by using proper preservatives and storage methods. EDTA, as mentioned earlier, is a commonly used preservative for long-term DNA storage. Sample containers should also be sterile and airtight to prevent contamination. Regularly checking and monitoring the storage conditions can also help ensure the quality of the DNA remains intact.

5. Are there any potential risks or concerns with storing human DNA at room temperature for long periods of time?

There are some potential risks and concerns with storing human DNA at room temperature for long periods of time. One of the main concerns is the potential for sample contamination, which can lead to inaccurate results. It is important to properly label and store samples to prevent cross-contamination. Additionally, unexpected changes in temperature and humidity levels can also affect the quality of the DNA. Regularly monitoring and maintaining stable storage conditions can help mitigate these risks.

Similar threads

  • Biology and Medical
Replies
15
Views
2K
Replies
2
Views
3K
Replies
5
Views
2K
  • Biology and Medical
Replies
2
Views
15K
  • Biology and Medical
Replies
4
Views
17K
  • Sci-Fi Writing and World Building
Replies
11
Views
1K
  • Biology and Medical
Replies
11
Views
5K
  • Biology and Medical
Replies
16
Views
5K
  • General Engineering
Replies
13
Views
2K
Replies
12
Views
966
Back
Top