title: Optimization of influencing factors of nucleic acid adsorption onto silica-coated magnetic particles: application to viral nucleic acid extraction from serum.
abstract: We present a detailed study of nucleic acid adsorption onto silica-coated magnetic particles in the presence of guanidinium thiocyanate, and extraction of nucleic acid from two important transfusion-transmitted viruses using these particles. Silica-coated magnetic particles were prepared by encapsulating Fe3O4 nanoparticles with tetraethylorthosilicate (TEOS) hydrolysis. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), dynamic light scattering (DLS) and vibrating sample magnetometer (VSM) were used for particle characterization. The results indicate that silica-coated magnetic particles are spheroid with a narrow hydrodynamic size distribution of about 500nm. VSM data indicates that these particles display paramagnetic behavior with saturation magnetization of about 30emu/g. The adsorption capacities were evaluated with DNA from salmon sperm and RNA of Escherichia coli strain JM109 in the presence of guanidinium thiocyanate. The maximum of adsorption is up to 10.6mg DNA or 7.7mg RNA per 1g of silica-coated magnetic particles with 4M guanidinium thiocyanate (GTC) at pH 5.5 without adding ethanol. The influencing factors were analyzed in term of the adsorption of nucleic acids onto silica-coated magnetic particles. The adsorption capacity in acidic condition is found to be larger than that in alkaline condition and increases with adding equivalent volume of ethanol. A simple method was therefore established to extract nucleic acids of two important transfusion-transmitted viruses from serum and compared with the commercial kits. The results indicate that the extraction method based on silica-coated magnetic particles can be adapted to rapidly and facilely isolate viral nucleic acid for diagnosis of viral infection from serum within 30min, irrespective of genome compositions of virus.
authors.affiliation: State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China; Beijing Entry-Exit Inspection and Quarantine Bureau, Beijing 100026, China; CAS Key Laboratory of Measurement and Standardization for Nanotechnology, National Center for Nanoscience and Technology, Beijing 100190, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Sun
authors.affiliation: Beijing Entry-Exit Inspection and Quarantine Bureau, Beijing 100026, China.
authors.forename: Congliang
authors.initials: C
authors.lastname: Deng
authors.affiliation: Beijing Entry-Exit Inspection and Quarantine Bureau, Beijing 100026, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Beijing Entry-Exit Inspection and Quarantine Bureau, Beijing 100026, China.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Zhao
authors.affiliation: CAS Key Laboratory of Measurement and Standardization for Nanotechnology, National Center for Nanoscience and Technology, Beijing 100190, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Tang
authors.affiliation: CAS Key Laboratory of Measurement and Standardization for Nanotechnology, National Center for Nanoscience and Technology, Beijing 100190, China.
authors.forename: Renxiao
authors.initials: R
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China. Electronic address: xiaq@seu.edu.cn.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Xia
authors.affiliation: Grirem Advanced Materials Co., Ltd., National Engineering Research Center for Rare Earth Materials, Beijing 100088, China; General Research Institute for Nonferrous Metals, Beijing 100088, China.
authors.forename: Wenlong
authors.initials: W
authors.lastname: Yan
authors.affiliation: CAS Key Laboratory of Measurement and Standardization for Nanotechnology, National Center for Nanoscience and Technology, Beijing 100190, China. Electronic address: gegl@nanoctr.cn.
authors.forename: Guanglu
authors.initials: G
authors.lastname: Ge
mesh_terms: D000327:Adsorption; D000818:Animals; D004247:DNA / Q000737:chemistry; D005290:Ferric Compounds / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D060328:Magnetic Phenomena; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D009696:Nucleic Acids / Q000097:blood* / Q000302:isolation & purification*; D012313:RNA / Q000737:chemistry; D012474:Salmon; D012821:Silanes / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D005290:Ferric Compounds; D009696:Nucleic Acids; D012821:Silanes; C000499:ferric oxide; C040733:tetraethoxysilane; D012313:RNA; D012822:Silicon Dioxide; D004247:DNA
keywords: Guanidinium thiocyanate; Nucleic acid; Silica-coated magnetic particles; Transfusion-transmitted virus