A microfluidic multi-injector for gradient generation
A microfluidic multi-injector for gradient generation
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DOI：
10.1039/b512667c
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发表时间：
2006-06-01
期刊：
影响因子：
6.1
通讯作者：
Jeon, Noo Li
中科院分区：
文献类型：
--
作者：
Chung, Bong Geun;Lin, Francis;Jeon, Noo Li
本文介绍了一种可产生可溶性分子时间和空间浓度梯度的微流控多进样器。与传统的基于玻璃微量移液器的产生单一梯度的方法相比，MMI利用多个脉动注射器的微流体集成和致动来产生先前不可能的任意重叠梯度。MMI器件采用多层软光刻技术在聚二甲基硅氧烷（PDMS）中制造，由流体通道和控制通道组成，控制通道具有可控硅驱动的片上阻挡阀。芯片上阀门的重复致动控制溶液的脉动释放，从而在孔口周围建立微观化学梯度。每个驱动循环释放的溶液体积范围从30皮升至数百皮升，并随阀门打开的持续时间线性增加。测量的梯度分布的形状与模拟的扩散分布从一个点源。使用优化的脉冲序列，可以在10分钟或更短时间内获得稳态梯度曲线。生成并表征了来自2个进样器的重叠梯度，以突出MMI相对于传统微量移液管测定的优势。MMI平台应该是有用的基础和广泛的应用研究的趋化性和轴突的指导。
This paper describes a microfluidic multi-injector (MMI) that can generate temporal and spatial concentration gradients of soluble molecules. Compared to conventional glass micropipette-based methods that generate a single gradient, the MMI exploits microfluidic integration and actuation of multiple pulsatile injectors to generate arbitrary overlapping gradients that have not previously been possible. The MMI device is fabricated in poly(dimethylsiloxane) (PDMS) using multi-layer soft lithography and consists of fluidic channels and control channels with pneumatically actuated on-chip barrier valves. Repetitive actuation of on-chip valves control pulsatile release of solution that establishes microscopic chemical gradients around the orifice. The volume of solution released per actuation cycle ranged from 30 picolitres to several hundred picolitres and increased linearly with the duration of valve opening. The shape of the measured gradient profile agreed closely with the simulated diffusion profile from a point source. Steady state gradient profiles could be attained within 10 minutes, or less with an optimized pulse sequence. Overlapping gradients from 2 injectors were generated and characterized to highlight the advantages of MMI over conventional micropipette assays. The MMI platform should be useful for a wide range of basic and applied studies on chemotaxis and axon guidance.