Abstract
BACKGROUND: Nocardia species have a complex cell wall structure similar to that of mycobacteria, and the extraction of DNA from this bacterium is extremely difficult. Currently, to identify Nocardia species particularly, it is essential to utilize molecular techniques. AIMS: In the present study, we investigated STET (sodium chloride-TRIS-EDTA-triton) buffer for the extraction of high-quality genomic DNA from 20 clinical and environmental isolates. MATERIALS AND METHODS: The extracted DNA was evaluated for portion of the 16S rRNA, 65-kDa heat-shock protein and 16S rRNA genes via polymerase chain reaction. RESULTS: The extracted DNA had high molecular mass, and its concentration and purity was suitable when tested in 1% agarose gel, and using UV spectrophotometry. Amplification of three different genes was successfully performed. CONCLUSION: This paper reveals an inexpensive, reproducible and efficient method of DNA extraction from Nocardia species, which is appropriate for accurate identification of this bacterium via polymerase chain reaction and polymerase chain reaction-restriction fragment length polymorphism.