Continuous flow microfluidic device for cell separation, cell lysis and DNA purification

A novel integrated microfluidic device that consisted of microfilter, micromixer, micropillar array, microweir, microchannel, microchamber, and porous matrix was developed to perform sample pre-treatment of whole blood. Cell separation, cell lysis and DNA purification were performed in this miniaturized device during a continuous flow process. Crossflow filtration was proposed to separate blood cells, which could successfully avoid clogging or jamming. After blood cells were lyzed in guanidine buffer, genomic DNA in white blood cells was released and adsorbed on porous matrix fabricated by anodizing silicon in HF/ethanol electrolyte. The flow process of solutions was simulated and optimized. The anodization process of porous matrix was also studied. Using the continuous flow procedure of cell separation, cell lysis and DNA adsorption, average 35.7 ng genomic DNA was purified on the integrated microfluidic device from 1 μL rat whole blood. Comparison with a commercial centrifuge method, the miniaturized device can extract comparable amounts of PCR-amplifiable DNA in 50 min. The greatest potential of this integrated miniaturized device was illustrated by pre-treating whole blood sample, where eventual integration of sample preparation, PCR, and separation on a single device could potentially enable complete detection in the fields of point-of-care genetic analysis, environmental testing, and biological warfare agent detection.