CTAB Extraction Solution

DNA extraction from plant cells is very difficult due to the presence of a rigid cell wall surrounding the plant cells. CTAB is used to break open the plant cells and solubilize its contents. The extraction process involves breaking or digestion of cell wall in order to release the cellular constituents. This is followed by disruption of the cell membrane to release the DNA into the extraction buffer. The released DNA should be protected from endogenous nucleases. EDTA is often included in the extraction buffer to chelate magnesium ions, a necessary co-factor for nucleases. The initial DNA extracts often contain a large amount of RNA, proteins, polysaccharides, tannins and pigments which may interfere with the extracted DNA and difficult to separate. Most proteins are removed by denaturation and precipitation from the extract using chloroform and octanol. RNAs on the other hand are normally removed by treatment of the extract with RNase A. The DNA is precipitated and washed in organic solvents before redissolving in aqueous solution.