Magnetic-bead-based microfluidic systems for detection of genetic diseases

The current study presents a new magnetic-bead-based microfluidic platform integrating several modules, including a human WBC (white blood cells) pretreatment module, a DNA extraction module and a nucleic acid amplification module for fast detection of genetic diseases by utilizing the MEMS (micro-electro-mechanical-systems) technologies. By using antibodies-coated magnetic beads, WBC can be purified and enriched, followed by extracting the genomic DNA utilizing the charge switchable DNA-specific magnetic beads in the lysis solution. Then, the specific genes associated with genetic diseases can be amplified and analyzed during the PCR (polymerase chain reaction) process. A new membrane-type micro-mixer was proposed for mixing the WBC with CD15/CD45-coated magnetic beads during incubation process. A circular microcoils array was developed for purification and enrichment of WBC. A new two-way circular pneumatic micro-pump and a bio-separator/micro-reactor were also integrated for genomic DNA extraction and bio-reaction. The extracted DNA can be transported automatically to a micro PCR chamber for fast nucleic acid amplification. The developed system may provide a powerful platform for WBC sample pre-treatment and fast diagnosis of genetic diseases.