DNA Precipitation

Overview

The goal of this protocol is to precipitate DNA, as the name says. This is usually coupled with phenol chloroform extraction and is used as a way of purifying nucleic acids. This can also be used as a method for changing what solution or buffer your nucleic acid is in.

This protocol also works for RNA precipitation (take care to us RNAse free materials in this case).

Materials

List reagents, supplies and equipment necessary to perform the protocol here. For those materials which have their own OWW pages, link to that page. Alternatively, links to the suppliers' page on that material are also appropriate.

• 3M NaOAc pH 5.2
• EtOH 95%
• Glycogen (optional)

Procedure

1. 1/10 volume NaOAc.
2. 1ul Glycogen.
3. 2 volumes EtOH.
4. -20°C overnight or 30min -80°C.
5. Centrifuge >12k G for at least 15 mins.
6. Remove supernatant
7. Resuspend in desired volume of water/buffer

Notes

• Ryan R Hurtado 17:21, 22 April 2008 (EDT):

-20°C for an hour is fine for using larger (1mL of bacterial culture, plasmid) amounts of DNA

The DNA pellet will not always be visible depending on how much DNA you are precipitating. So always take care in loading your samples in the centrifuge to remember the direction they are facing. The DNA pellet will be on the part of the tube facing the outside of the centrifuge.

References

Relevant papers and books

1. Goldbeter A and Koshland DE Jr. An amplified sensitivity arising from covalent modification in biological systems. Proc Natl Acad Sci U S A. 1981 Nov;78(11):6840-4. DOI:10.1073/pnas.78.11.6840 |
2. JACOB F and MONOD J. Genetic regulatory mechanisms in the synthesis of proteins. J Mol Biol. 1961 Jun;3:318-56. DOI:10.1016/s0022-2836(61)80072-7 |
3. ISBN:0879697164

Contact

• Who has experience with this protocol?

or instead, discuss this protocol.