Hey everyone. I collected some leaf tissue samples from the plant Phragmites australis from which I am hoping to extra DNA for sequencing. I will be extracting DNA using Qiagen DNeasy Plant Mini Kits. I was in a rush when storing them, however, and I just placed them in ziploc bags in the freezer at -20oC. They had been kept in the same bags in a cooler while transporting them from the field to the lab.
Is this going to be okay? They've been in there for a few weeks at this point and it may be another few weeks or even a month or two before we will be able to begin lab work. Would it be possible to move them to -70oC now or is it too late? Can they be thawed and dried at room temp in silica gel? Just wondering what my options are here and what I need to take into consideration. At this point, it is too late in the season to collect new tissue samples so this is all that I have to work with.
Thanks in advance!
Hi Jordan,
I guess you can still isolate DNA from tissue, however, I would highly recommend to move them to -80°C in order to preserve the DNA. Ideally, isolation should be done immediately to ensure good quality and high amounts of DNA.
Good luck!
They should be just fine. I'd also suggest moving them to the -80* freezer if you have space. What you want to avoid is multiple freezing and thawing cycles.
Jordan Nikkel
DNA is a very stable molecule and storing samples at even 4 °C be okay. You are taking DNA from a grass growing at ~ 25-30 °C. If the DNA is in tissue and the tissue is not rotten, it is no problem at refrigerated temperature, its perfect.
However, for a small period of time storing tissue samples at -20 °C would be absolutely fine or even more than enough. DNA sequencing also is a robust method and not particularly prone to small degradation of DNA molecule (considering all the process from start to end).
Conclusion:
In my personal opinion, if you are thinking to extract (in few weeks or months) the DNA from those samples which are stored at -20 °C it perfectly fine. You don't need to worry about them to store them at -70 °C. However, if you want them to move them from -20 to -70 °C, you can do that.
Abhijeet Singh Katie A Burnette Markus Huemer
Thanks for all the help!
Yes you can store the tissues at -20 degree and can extract the DNA later.
Dear Jordan Nikkel,
You can also use DNA Shield solutions and safely store the sample at room temperature or in the freezer.
https://www.nordicbiosite.com/product/BioSite-R1200-25/DNARNA-Shield-2X-Concentrate
In my opinion, you can store the samples at -20 degrees without any doubt...
As DNA is stable, you can store the samples at -20 °C, although -80°C is better for preservation.
Yes you can stored it at -20 degree and can extract the DNA later.
I think they should be okay. I also recommend storing them at -80* freezer, to keep the samples as they in natural condition.
- Badges
- Science method