Evaluation of the effect of magnetic nanoparticles on extraction of genomic DNA of Escherichia coli

The initial step in molecular biology and genetic engineering fields are the finding of optimal methods for the extraction of the genomic DNA from microorganisms and cells. There are several methods for the extraction of bacterial DNA and the use of magnetic nanoparticles is a novel method for the isolation of nucleic acid. In the present study, the synthesized magnetic nanoparticles were used to extract the genomic DNA of Escherichia coli. In this study, the naked (Fe3O4) and coated (Fe3O4/SiO2; Fe3O4/SiO2/TiO2) magnetic nanoparticles were synthesized by precipitation methods. The purity of the product was assessed using energy-dispersive x-ray spectroscopy (EDS) and x-ray crystallography. The morphology and size of specimens were observed via field emission scanning electron microscopy (FESEM). The efficacy of the synthesized nanoparticles in genomic DNA extraction from Escherichia coli strain ATCC25922 was compared. The quality of the resulting DNA was analyzed by NanoDrop spectrophotometer, agarose gel electrophoresis, and PCR assays. According to the findings of SEM, the size of Fe3O4/SiO2/TiO2 magnetic nanoparticles was about 43.25 nm (Fe3O4/SiO2/TiO2). XRD analysis showed that the product nanoparticles were synthesized without impurities. The extraction results also showed that the purity and concentration of extracted genomic DNA by coated magnetic nanoparticles in comparison with naked magnetic nanoparticles were higher. In addition, the use of 0.4 mg of nanoparticles and 80% polyethylene glycol were optimal conditions for achieving a higher quality of DNA. According to the obtained results, the coated magnetic nanoparticles Fe3O4/SiO2/TiO2 can be used to extract genomic DNA of high quality from gram-negative bacteria.