Simple salting-out method for DNA extraction from formalin-fixed, paraffin-embedded tissues

The aim of this study was to standardize a method of DNA extraction from formalin-fixed and paraffin-embedded tissues (PETs) using a salt solution to precipitate protein and isopropanol to precipitate DNA. The samples were submitted to a DNA extraction method in which two different concentrations of ammonium acetate (2 and 4 M) were compared with a phenol–chloroform extraction method and with a commercial DNA isolation kit. DNA was qualified and quantified by spectrophotometer analysis, electrophoresis, and amplification by PCR. The 167 and 268 bp fragments of APC and β-globin genes, respectively, were amplified equally from DNA extracted by all tested methods and in all cases. However, the 536 bp fragment of β-globin gene was not amplified in all cases. According to our results, the extraction method using ammonium acetate proved to be simple and suitable for obtaining DNA of good quality, which can be easily amplified by PCR.