Comments
The cationic detergent cetyltrimethylammonium bromide (CTAB) is used to liberate and complex with total cellular nucleic acids. CTAB forms an insoluble complex with nucleic acids when the initial NaCl concentration is lowered to ~0.5 M. Polysaccharides, phenolic compounds and other enzyme-inhibiting contaminats found in plant cells are efficiently removed in the supernatant because most do not precipitate under these conditions (1).
Literature
(1) Ausubel, F.A., Brent, R., Kingston, R.E., Moore, D.D., Seidman, J.G., Smith, J.A. & Struhl, K. (eds.) (2001) Current Protocols in Molecular Biology. Page 2.3.5 (Suppl. 45) Greene Publishing & Wiley-Interscience, New York.