Dear all. We need to sample insects, store them upon collection and ship them internationally. Sampled will later be processed for DNA extraction and NGS sequencing.
Keeping all this in mind, can anybody recommend the best method/buffer to store the sample? RNAlater? Ethanol 70 or 100%?
Methods that are acceptable for international courier shipping would be preferred, as we have already lost some sampled due to missing stamps or the like.
Thanks
Hi Francesco, I have been shipping mosquitoes with different methods from collection sites to our lab where we extract DNA/RNA, that we send to the companies for WGS or RNA-seq.
We got the best extractions using DNA/RNA shield (ZymoTech) or a similar product. We homogenize the insect in a small volume of DNA/RNA shield with an electric pestle or better a tissue lyser and use a precipitation-based DNA extraction method (eg. Promega Wizard kit, DNAzol, Phenol-Chloroform...). You can also store the entire insect if you want and homogenize it later.
This method also inactivates any infectious material and protects the sample from heat, freezing-defreezing etc. so it is pretty "custom-friendly", also for the US, and you can write on the lable that you're shipping non-infectious DNA.
You can store the samples in 70% ethanol but there is a little loss of material in my opinion or (very complicated) ship it in dry ice.
If you're going to have the DNA extracted by the company just talk with them before choosing the conservation medium because in my experience (based on different companies in Italy, US and China) they use quick and standard extraction methods and they often do terrible extractions. So ask them if they can process the sample you would send them and remind them that it is a delicate sample and that it needs to be extracted in a "special" way, or they'll just treat as if it was a "classic" soft tissue sample.
Francesco Nardi
Since you are interested in DNA, the method of transport is not very crucial. sure you can use RNA later, but it would be little expensive. But in my opinion storage in TBE buffer can be equally good. Transport can also be done on dry ice which is very good and safe way to transport the samples. You may choose what suits you best according to your carrier.
And as you mentioned, I guess your problem is not the method itself. Rather the problem was the carrier if the stamps etc. were missing. They can still happen again irrespective of how you store the sample or how you transport. Maybe check a good reliable postal carrier for your samples.
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