Comparison of Ten DNA Extraction Protocols from Wood of European Aspen (Populus tremula L.)

It is difficult to extract pure high quality DNA from tree tissues, which may not be amenable to advances in extraction methods suitable for other plants. This is especially true for wood samples, that are easy to collect from mature trees, but difficult to handle afterwards. We have compared ten different DNA extraction techniques that are known to be effective in plant genomic DNA isolation. We have used six well known DNA extraction techniques as well as four commercially available kits for DNA extraction from European aspen (Populus tremula L.) trees grown in the forest. The quality of DNA was tested by spectrophotometry and PCR amplification of the chloroplast intergenic spacer region between tRNR L-F genes. The results indicate the success using SDS, protein precipitation and CTAB DNA extraction techniques, while other methods (CTAB precipitation, Guanidinium isothiocyanate and alkaline isolation) provided DNA of poor quality or contaminated DNA not suitable for PCR. Commercially available kits also gave different results: DNA isolation reagent for genomic DNA with Plant AC reagent (Applichem) provided DNA with strong contamination, while Nucleospin Plant II (Macherey-Nagel), Genomic DNA purification kit (Fermentas) and innuPREP Plant DNA Kit (Analytikjena) yielded good quality and satisfactory concentration of genomic DNA.