The volume is not the issue, 10ml is no problem. But if the concentration of DNA in the sample is low your recovery may not be good. After adding salt and vortexing, add ethanol and chill to enhance recovery. You can also enhance recovery with a carrier species such as tRNA or glycogen. Good luck!

Generally the method you list is correct 1:10 vol NaOAC and 2.5 vol EtOH. You will have losses if your DNA is with low concentration - follow Richard's advice. Alternatively you may use column (Qiagen) purification 

Just curious how much DNA do you need for NGS? Also use TE to dissolve your DNA, not H2O

Hi Richard and Petre, thank you both for your responses. 

I'm glad to hear 10 mL is not a problem. We need a total of 5 ug of DNA at a concentration of 200 ng/uL, for NGS. Estimating a loss of 20% DNA, I have calculated that I will need 10 mL of that particular sample in order to get 100 uL of around 200 ng/uL (in order to supply a final amount of 5 ug of DNA for NGS). The company we are contracting to perform the work have specified that the DNA should be in molecular grade water.

This particular sample is the most dilute sample I have. I need to concentrate a few others, but the max. volume to be concentrated is 3 mL. I just wanted to see if someone had done as much as 10 mL. We looked into the Sartorius Vivacon 2 devices, however because we only need to them for a few samples, they weren't economically favourable. I'm glad I can use the NaOAc method.

Thank you both, again! This is great news.

If the company that you contracted ask for DNA to be dissolved in H2O, I think you should seriously consider changing them. Best of luck!

Why don't you use isopropanol (1 volume) instead of ethanol (2.5 volume). Isopropanol is much better when precipitating large volumes of DNA. 

Agree with Amal, isopropanol will do as well. If you really want to reduce volume you could use higher alcohols - n- butanol will suck the water out, and will separate in two phases. It is another way to concentrate DNA in water solutions, however DNA precipitation is usually more straight-forward.

i dont know much but iam telling this thing based on my experience use Isopropanol it is much better when precipitating large volumes of DNA. thanks and all the best

So, I performed a few yesterday using NaOAc and EtOH. Today I used isopropanol and my yields were extremely low...I don't know if I did something wrong. They are 10 times lower that estimated. Any ideas?

I added:

1:10 3M NaOAc

Equal volume of isopropanol (as DNA)

Vortex to mix, stored on ice for 20'. Cen. at max. speed for 15 min, removed supernatant

Washed with 70% EtOH, cen. 2' max. speed, removed supernatant and then dried the pellet under the flame. 

I actually split the total combined start volume for each individual sample (DNA, NaOAc, isopropanol), across multiple 1.5 mL tubes so that I could cen. at a higher speed than the 10 mL rotor would allow. To combine pellets, I added 100 uL MG water, heated to 55C for 2' to help the DNA dissolve, transferred that 100 uL to the next tube and heated that at 55C for 2'. I repeated this until all pellets were combined. I did this same process for the samples I concentrated yesterday - the only difference today was the use of isopropanol. 

Any thoughts?

Hi, Natalie. Isopropanol (IPrOH) will work, but I am not sure of the correct volume ratio. Your salts ratio is correct. IPrOH may also bring down a lot of salt, and there may be increased risk of losing the pellet during subsequent 70% EtOH washes. I don't know what you mean by drying under flame, but if too dry, the DNA will not properly rehydrate in water. Let it dry at room temp or briefly speedvac but don't overdry. I would resuspend in 10 mM tris pH 8 (no EDTA for subsequent enzyme operations) but talk to your NGS service about buffer pH/compatibility - they are probably also concerned about EDTA. Maybe resuspend DNA in something compatible with their first enzyme operation, such as their buffer? Or resuspend in Tris and then desalt with spin column. Very pure water is pH ~5.5 due to dissolved CO2 as carbonate. You can elute DNA off of a silica column in water but resuspending a pellet is different. Cheers & good luck.