Purification Genomic DNA from Soil_Throughing Method

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(Harnpicharnchai et al., 2007)

One among numerous problem from soil DNA genomic is the present of inhibitors. To remove them, try this technique.......simple, cheap, and clean. No need to use commercial kit.....


1. Subject unpurified genomic DNA from soil to electrophoresis in TAE or
TBE agarose gel (0.8-1%) in the presence of 0.1-0.5 μg/mL of ethidium
bromide at 85 volts for approximately 45 minutes.
2. Make a rectangular well (trough) approximately 0.5-1 cm wide just below
the DNA band directly in front of the path of DNA migration by a sharp
scalpel.
3. Remove excess agarose in the well. Fill well thoroughly with troughing
buffer (25% PEG8000 in TAE or TBE buffer).
4. Do additional electrophoresis (for approximately 30 minutes) until the DNA
band was in the middle of the well.
5. Collect DNA in a clean tube.
6. Extract DNA once with chloroform:isoamyl alcohol (24:1 v/v).
7. Precipitate DNA with 2 volumes of ethanol at –80°C for 25 minutes.
8. Spin at 13,000 rpm for 30 minutes.
9. Discard supernatant. Wash DNA pellet with 70% ethanol. Spin at 13,000
rpm for 25 minutes.
10. Resuspend DNA in 20 μL of water or TE buffer.


For further detail, please refer to this Article:

Harnpicharnchai,P. etal(2007) An efficient purification and fractionation of genomic DNA from soil by modified troughing method.Letters in Applied Microbiology. 45: 387–391