Isolation of PCR-ready genomic DNA from Aspergillus niger cells with Fe3O4/SiO2 microspheres

•Core–shell structured Fe3O4/SiO2 microspheres were obtained.•The microspheres exhibit superparamagnetism, high magnetization, and good dispersion.•Genomic DNA from Aspergillus niger NA1003 cells was isolated with the microspheres.•Magnetic separation yields PCR-ready genomic DNA and satisfying productivity.•Complexation mechanism of DNA with silica-coated microspheres is discussed.

Silica-coated magnetic microspheres present a promising candidate for applications in bioseparation, drug delivery, and catalysis. In this paper, we report on the synthesis of core–shell structured Fe3O4/SiO2 microspheres via a modified Stöber process. The magnetic composite microspheres exhibit superparamagnetism, high saturation magnetization, and good dispersion. The samples were characterized with XRD, FTIR, TEM, and VSM techniques, and further tested as adsorbents for purification of genomic DNA from Aspergillus niger NA1003 cells. The purified genomic DNA was analyzed by agarose gel electrophoresis and examined by polymerase chain reaction (PCR) amplification. The magnetic isolation protocol presents genomic DNA with PCR-ready quality and shows superior to the conventional phenol–chloroform extraction.

Graphic abstractSuperparamagnetic core–shell structured Fe3O4/SiO2 microspheres were prepared via a modified Stöber process and further tested as adsorbents for isolation of genomic DNA from Aspergillus niger NA1003 cells, yielding PCR-ready genomic DNA and satisfying productivity.Figure optionsDownload full-size imageDownload as PowerPoint slide