Computer, Electrical and Mathematical Sciences & Engineering division, 4700 King Abdullah University of Science and Technology , Thuwal, Makkah 23955, Kingdom of Saudi Arabia.
Biological and Environmental Sciences & Engineering division, 4700 King Abdullah University of Science and Technology , Thuwal, Makkah 23955, Kingdom of Saudi Arabia.
Biomicrofluidics. 2014 Jun 16;8(3):034114. doi: 10.1063/1.4883855. eCollection 2014 May.
This study describes the development and testing of a magnetic microfluidic chip (MMC) for trapping and isolating cells tagged with superparamagnetic beads (SPBs) in a microfluidic environment for selective treatment and analysis. The trapping and isolation are done in two separate steps; first, the trapping of the tagged cells in a main channel is achieved by soft ferromagnetic disks and second, the transportation of the cells into side chambers for isolation is executed by tapered conductive paths made of Gold (Au). Numerical simulations were performed to analyze the magnetic flux and force distributions of the disks and conducting paths, for trapping and transporting SPBs. The MMC was fabricated using standard microfabrication processes. Experiments were performed with E. coli (K12 strand) tagged with 2.8 μm SPBs. The results showed that E. coli can be separated from a sample solution by trapping them at the disk sites, and then isolated into chambers by transporting them along the tapered conducting paths. Once the E. coli was trapped inside the side chambers, two selective treatments were performed. In one chamber, a solution with minimal nutrition content was added and, in another chamber, a solution with essential nutrition was added. The results showed that the growth of bacteria cultured in the second chamber containing nutrient was significantly higher, demonstrating that the E. coli was not affected by the magnetically driven transportation and the feasibility of performing different treatments on selectively isolated cells on a single microfluidic platform.
本研究描述了一种用于在微流环境中捕获和隔离带有超顺磁珠（SPB）标记的细胞的磁性微流控芯片（MMC）的开发和测试，用于选择性治疗和分析。捕获和隔离分为两个单独的步骤；首先，通过软铁磁体磁盘实现标记细胞在主通道中的捕获，其次，通过金（Au）制成的锥形导电路径将细胞运输到侧室进行隔离。进行了数值模拟，以分析磁盘和导电路径的磁通和力分布，用于捕获和运输 SPB。使用标准微制造工艺制造了 MMC。用标记有 2.8μm SPB 的大肠杆菌（K12 株）进行了实验。结果表明，通过在磁盘位置捕获它们，可以将大肠杆菌从样品溶液中分离出来，然后通过沿着锥形导电路径将它们运输到腔室中进行隔离。一旦大肠杆菌被捕获在侧腔室内部，就进行了两种选择性处理。在一个腔室中添加了营养含量最低的溶液，而在另一个腔室中添加了含有必需营养的溶液。结果表明，在含有营养物质的第二个腔室中培养的细菌的生长明显更高，这表明细菌不受磁性驱动运输的影响，并且可以在单个微流控平台上对选择性分离的细胞进行不同处理。
