A simple and efficient protocol for isolation of high molecular weight DNA from filamentous fungi, fruit bodies, and infected plant tissues

The short protocol given below combines inactivation of proteins by SDS/Proteinase K with precipitation of acidic polysaccharides by hot CTAB in the presence of SDS and high salts and only a single selective precipitation of DNA with isopropanol. The method is appropriate for simultaneous processing of many samples because all steps can be donein Eppendorf tubes, it can also be scaled up easily for bulk preparations. A treatment with methanol containing 0.1% mercaptoethanol preceding DNA extraction was performed when basidiocarps and plant tissues contained large amounts of reactive compounds (resins, phenolics) interfering with solubilization of DNA. Methanol extraction was found to be superior over other solvents such as acetone. We isolated DNAs from a wide variety of fungi including Fusarium, Pseudocercosporella, Phytophthora, Setosphaeria, Armillaria , Heterobasidion, Boletus, Russula, Lactarius, Suillus, Cortinarius , and from conifer roots and needles (Picea abies, Pinus sylvestris ).