http://www.nature.com/nprot/journal/v2/n5/full/nprot.2007.195.html

This is the best so far. It works.

Thank you very much Lekha. This is a very good protocol but I was looking for a commercial product, I know that are expensive but usually work better than lab-made ones and if you have a lot of samples you will at the end save time.

Try Qiagen Soil Kit. It might work.

we use the MOBIO kits http://www.mobio.com/environmental-application/ with good results.

UltraClean® Soil DNA Isolation Kit (Mo Bio) - the best

i've tried with Mo Bio soil DNA isolation kit, same with VIctoria , and its good

Usually,we use either Isoplant II (Nippongene, Tokyo, Japan) or UltraClean® Soil DNA Isolation Kit (Mo Bio).

You can use MOBio soil DNA isolation kit, use multiple columns for a single sample.

Saline (40 mL) containing 6 g soil is filtrated with a 40 µm nylon mesh and the filtrate is centrifuged at 500 × g. The supernatant is centrifuged at 15,000 × g and 4˚C for 20 min to collect the soil bacteria. DNA was isolated from the precipitate using Isoplant II or UltraClean® Soil DNA Isolation Kit (Mo Bio).This protocol is simple and reproducible.

I vote for UltraClean® Soil DNA Isolation Kit (Mo Bio) as the best option. I found it to be better than Qiagen kits for this type of application.

Thank you so much for the many replies. I have used the PowerSoil® DNA Isolation Kit (maybe is the same of the UltraClean® Soil Kit) with great and clean result, but as you probably know the recommended soil quantity is between 0.25 and 0.5 g of soil... and that is not very much. The multiple extraction from the same sample could be although a way to avoid this problem. I saw that MoBio produce the PowerMax® Soil DNA Isolation Kit (10 prep) for up to 10g soil start , it would be perfect but also very expensive for 60 samples... Never heard about Isoplant II... Does it really work well?

Yes, we use this kit to isolate environmental DNA and RNA.

The commercial kit iSoil (Nippongene) and a Fast DNA Spin Kit for Soil (Qbiogene, Carsbad, CA) may also be effective for extraction of environmental DNA in soil samples.

Hi, why using a kit? I always use simple CTAB-Phenol-Chloroform extraction for all my samples (soil, activated sludge, digested sludge, wastewater) and it works perfect. Cheap and easy. If needed I can porvide a modified protocol.

To our own experience the best one is from the "MP biomedicals" compagny but it requires a specific cell tissue homogeneizer (the Fast Prep).

I hate to be old school....I did my PhD before the age of "kits", but if it were me, I would look up some old (pre-kit) publications on extraction of DNA from soil and use those protocols for handling large soil samples. Kits are great tool and are a tremendous time saver, but are generally designed for specific applications, which may not be suitable for what you want to accomplish. If you find a kit that does what you want (and I hope you do), simply ignore this reply.

Hi, I used to extract DNA from soil the MoBio Kit and it's running good.

it' s built for 1g of soil but in the protocol there are the suggestion for using it for more than 1g! or ask to the productor.

In order to study the biodiversity of soil samples polluted and unpolluted with hydrocarbons and to investigate the effect of bioremediation tretaments on soil biodiversity, we currently make DNA extraction.

We use the following commercial kits for the extraction Total bacterial DNA samples:

a. PowerSoilTM DNA Isolation Kit, Mobio Laboratories, Inc. for 1g sample

b. PowerMaxTM DNA Isolation Kit, Mobio Laboratories, Inc, for 10 g sample;

c. Fast ID Genomic DNA Extraction Kit, Genetic ID NA, Inc. to 1g of sample.

Also, in the case of some sandy soil samples and samples of soil treated with

FENTON reagent, we have used the protocol described by Hurt et al. [2001] due to the inability of the kits Commercial for extracting DNA from these samples. The protocol of Hurt et al. [Appl Environ. Microbiol.2001. 67:4495] is a non-commercial extraction protocol and analyzed soil sample 2g​​.

The general conclusion of many studies was that:

The method of DNA extraction from soil introduces variations in the efficiency of extraction of bacterial populations that are reflected in the number of bands and in their intensity. The comparative study of protocols Mot Bio 1g, 10g Bio Mot, Fast ID and protocol Hurt al (2001) showed that detectable variations for the same soil analysis ranged around 15%.

But for me, PowerMaxTM DNA Isolation Kit, Mobio Laboratories, Inc, for 10 g sample would be a good option

I agree with Concepcion Calvo.×

Thank to all of you, it' incredible how many people can be interested to help each other... It seems that this community really works for research over than for researchers. Anyway, Bastian I will appreciate your modified C-Tab method, hope you can tell me where to find. Conception, thanks for reference paper of Hurt et al. (2001), comparisons of methods are always interesting and lightening. Enrico, I will for sure ask for a clarification about to use 1g with MoBio kit. A sort of homogenization of the soil before extraction could be indeed useful for all of you. Letitia you mentioned the Fast Prep, I must learn more about it... Thank you all of you!

Hi..can anyone suggest fungal DNA extraction protocol from soil samples. Thanks in advance..

We have used the fast prep for large soil samples with special adapter. But we have not been successful. In the final step the filters that must collect the DNA is always broken. So it is not a good idea to buy the Fast Prep adapter.

Thus, we have used the fast prep for 1 g several times with the same sample (5 times, 5 g), gathering all. And following the protocol of extraction and purification of DNA.

all kits are for 0.2-0.25 g soil. if you try to process more- they will choke. So I'd advise to just split your sample 5 ways, and process 0.2 g aliqots using 5 mini columns. then combine DNA

As mentioned before, there are kits for up to 10g of soil. Check for Fast DNA 50mL SPIN Kit for Soil and PowerMax Soil DNA Isolation Kits.