Using channel depth to isolate and control flow in a micro free-flow electrophoresis device
Using channel depth to isolate and control flow in a micro free-flow electrophoresis device
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DOI：
10.1021/ac060290n
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发表时间：
2006-08-01
影响因子：
7.4
通讯作者：
Bowser, Michael T.
中科院分区：
文献类型：
--
作者：
Fonslow, Bryan R.;Barocas, Victor H.;Bowser, Michael T.
研制了一种多深度微自由流电泳芯片（mu-FFE），分离通道深20 μ m，电极通道深78 μ m。由于通道高度的差异，电极通道中的缓冲液的线速度类似于分离通道中的缓冲液的线速度的15倍。先前的mu-FFE装置受到电极处电解产物形成的限制。这些电解产物表现为气泡，降低了电场并破坏了缓冲液流动曲线，限制了性能并阻止了连续操作。使用通道深度来控制电极上和分离通道中的缓冲液流有效地去除电解产物，从而允许连续操作。使用粒子测速仪确认通道中的线速度，并与使用润滑理论预测的值进行了比较。在观察到显著的焦耳加热之前，可以施加645 V的分离电势。这对应于分离通道中586 V/cm的电场，比我们以前的设计增加了4倍。使用新的mu-FFE装置证明了荧光标准品的分离。分辨率比我们以前的设计提高了1.3倍，即使在类似的条件下操作，这表明有效去除电解产物比最初想象的更重要。
A multiple-depth micro free-flow electrophoresis chip (mu-FFE) has been fabricated with a 20-mu m-deep separation channel and 78-mu m-deep electrode channels. Due to the difference in channel heights, the linear velocity of buffer in the electrode channels is similar to 15 times that of the buffer in the separation channel. Previous mu-FFE devices have been limited by electrolysis product formation at the electrodes. These electrolysis products, manifested as bubbles, decreased the electric field and disrupted the buffer flow profile, limiting performance and preventing continuous operation. Using channel depth to control buffer flow over the electrodes and in the separation channel effectively removes electrolysis products, allowing continuous operation. The linear velocities in the channels were confirmed using particle velocimetry and compared well with values predicted using lubrication theory. A separation potential of 645 V could be applied before significant Joule heating was observed. This corresponded to an electric field of 586 V/cm in the separation channel, a 4-fold increase over our previous design. A separation of fluorescent standards was demonstrated using the new mu-FFE device. Resolution increased by a factor of 1.3 over our previous design, even when operated under similar conditions, suggesting that effective removal of electrolysis products is more important than originally thought.