Magnetic Microsphere with Surface Charge Switching-based Microfluidic Chip for DNA Extraction

Self. made surface charge switching amino. SiO2@Fe3O4 magnetic composite microspheres were applied to microfluidic chip, and DNA solid phase extraction chip of polymethyl methacrylate (PMMA) was fabricated by laser etching and hot pressing bonding. The magnetic beads that could be controlled by permanent magnet were injected into the chip channel to obtain a magnetic bead chip for genomic DNA extraction in human whole blood. Under the optimized extraction conditions (with 80 mu g beads, flow rate for adsorption, elution and desorption were 10, 5 and 20 mu L/min, respectively), the extracted products were subjected to gel electrophoresis and PCR test. The results showed that the genomic DNA with high purity was extracted from the whole blood by magnetic bead microfluidic chip. The extraction efficiency was about 35%. The gel electrophoresis band of the extract was consistent with the genomic DNA extracted by commercial reagent kit. The extract solution could be used for further PCR reaction.