Yes, I think you can with ethanol precipitation as found in most DNA isolation/purification kits or use a DNA clean up kit. Sorry I can't advertise any!

Cheers

Monica-Lewinsky-Method might be helpful! :)

you can cut a small piece of filter paper and mark on it a place to where you pipet your DNA solution. You should just dry after pipetting and send it even in an envelope, so they can cut that place out and solubilise in water for analysis

I second Erman's answer, since it makes the DNA more stable while at room temperature during transit (relative to being in water), makes the samples less bulky, and is very easy to resuspend - the recipient just needs to put the paper into a tube with water.

However, if your shipping company or recipient is uncomfortable sending DNA that is not in a closed tube, you can always reprecipitate DNA with sodium acetate and ethanol with very little loss, and dry the pellet according to this protocol:

https://www.mlpa.com/WebForms/WebFormDBData.aspx?Tag=_wl2zCji-rCGANQgZPuTixn01pTTvcNt-SNVkcQD5y3xpa11bK1W4GRNLbjV7Lemdz9tEz0HK5jxaciubz5YRvA..

Drying down DNA in solution does work, however it normally requires waiting a long time and/or warming up the sample while it dries. This can degrade the DNA, and in the end you have a much higher concentration of salts (since they are in a buffer), that might interfere with downstream applications. This is why a precipitation approach is preferred.

Hi Nicholas!

There are two ways to send the DNA samples around the world. First one is recommended by Erman, second one depends on the DNA concentration, if it is high enough (above 100-200 microg/ml) you can take the samples (10-20 microL) and lyophilized them. Then make small packs and send them. Inform addressees that sample contains definite amount of DNA and TE salts.

If you need a dry pellet:

for 500µl DNA in TE in a 1.5ml tube

add 60µl Na Acetate buffer 3M

add 1ml absolute pre chilled EtOH

Mix

Place at -80ºC 20min or -20ºC overnight

Centrifuge 60min Maximum speed (13.000rpm) on bench centrifuge prechilled 4ºC or in cold room.

You should see a white pellet

Remove supernant carefully

Let it dry a RT or speedvac

I think it depends on how much DNA you have to play with/send, and what the recipients intend to do with it. Very small amounts (micrograms: OK for PCR/transformation) will not form a visible precipitate with ethanol, but you can add 1mg of glycogen to produce a visible pellet. After drying, that can be sent in heat seal plastic bags in a normal (air)mail envelope. And large (mg) amounts, ditto, but without glycogen. My experience is that a minus 80ºC or minus 20ºC step isnt needed, but you can test that yourself.

If you have no glycogen, spotting and drying onto clean filter paper as described by Erman, (and used by Monika Lewinsky but for a purpose that needs more explanation, please) is fine.

Freeze-drying will also work, but not ideal if large volumes are involved as you can end up with a bulky residue of Tris and EDTA . The residue would of course need to be dissolved in the same volume of water as the volume that was initially freeze-dried.

Thanks everyone for the great answers! I will test out the method outlines by Christophe. I'm working with between 3000 and 60 000 ng of DNA (based on nanodrop readings) so a pellet should form. I'm likely to try the filter paper method too as it seems like an easy way to post the samples. Could I combine them and pour the DNA pellet out onto the filter paper to dry after the EtOH precipitation?

I hope I am wrong, but I doubt if you will see a pellet. Add 1mg glycogen, and you surely will.

Yes you could dry off the pellet on fliter paper, but your recipients should dissolve the DNA in TE, not water, unless they intend to carry out PCRs.

2 micrograms of nucleic acids form visible ethanol/isopropanol precipitates in the 0.6-1.5 ml tube after centrifugation.