Phenol-chloroform extraction

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As a phenol-chloroform extraction , a biochemical DNA extraction method referred to, which in molecular biology for separation of proteins , DNA and RNA is used. The process is based on the different solubilities of the substances to be extracted in a two-phase emulsion . The phenol-chloroform extraction was developed by Piotr Chomczynski and Nicoletta Sacchi (see also RNA isolation ).

Separation principle

For the separation the solution to be treated is mixed with phenol , chloroform and a chaotropic denaturing agent (e.g. guanidinium thiocyanate or guanidine hydrochloride ). A two-phase system is formed in which the various macromolecules can be found in different layers. Proteins collect in the lower, organic phase (phenol and chloroform), while the RNA is dissolved in the upper (aqueous) phase. Most of the DNA is at the phase boundary. Nucleic acids can be precipitated selectively with ethanol or isopropanol , but the two phases should be separated beforehand. In order to purify DNA in a targeted manner using this method, the denaturant is dispensed with, so that the RNA is not dissolved and only the DNA can be found in the aqueous phase.

Individual evidence

  1. Chomczynski, P. & Sacchi, N. (1987): Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction. In: Anal. Biochem. 162: 156-159, doi : 10.1016 / 0003-2697 (87) 90021-2 .
  2. Chomczynski, P. & Sacchi, N. (2006): Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction: Twenty-something years on. In: Nature Prot. 1: 581-585, doi : 10.1038 / nprot.2006.83 .