Incubated protein reduction and digestion on an electrowetting-on-dielectric digital microfluidic chip for MALDI-MS.
Incubated protein reduction and digestion on an electrowetting-on-dielectric digital microfluidic chip for MALDI-MS.
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DOI：
10.1021/ac101833b
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发表时间：
2010-12-01
影响因子：
7.4
通讯作者：
Kim, Chang-Jin CJ
中科院分区：
文献类型：
--
作者：
Nelson, Wyatt C.;Peng, Ivory;Lee, Geun-An;Loo, Joseph A.;Garrell, Robin L.;Kim, Chang-Jin CJ
在电介质润湿(EWOD)芯片上实现了液滴的局部加热，并被证明加速了基质辅助激光解吸电离质谱仪(MALDI-MS)的胰酶消化反应、样品干燥和基质结晶。要实现这一点，需要通过开发具有闭环温度控制的多功能电极来扩展以前基于EWOD液滴的技术的功能，同时将整个系统的复杂性降至最低，并解决与快速蒸发相关的挑战。对于EWOD芯片的设计，我们讨论了用于驱动、局部焦耳加热和热温度传感的多功能表面电极的性能。此外，在多功能电极中形成亲水图案以控制蒸发液滴在电极上的位置。为了证明这项技术的能力和局限性，我们进行了三个实验，并使用MALDI-MS测量了结果：(I)在DTT中的二硫化胰岛素还原在一定范围的加热器温度(22至70°C)下，以显示热控制如何影响反应速度；(Ii)在DMSO中，在130°C下进行二硫化胰岛素还原，以演示在高沸点溶剂中的反应；以及(Iii)在22℃和40°C下对细胞色素c进行胰酶消化，以表明加热的液滴比未加热的液滴可以产生合理更高的肽序列覆盖率。尽管它们不能消除温度和浓度变化的影响，但这些实验证实，EWOD电极的热循环加快了空气中液滴的反应速度。
Localized heating of droplets on an electrowetting-on-dielectric (EWOD) chip has been implemented and shown to accelerate trypsin digestion reaction rates, sample drying, and matrix crystallization for matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS). Achieving this involved extending the functionality of previous EWOD droplet-based techniques by developing a multifunctional electrode with closed-loop temperature control, while minimizing overall system complexity, and addressing challenges associated with rapid evaporation. For the EWOD chip design, we discuss the performance of multifunctional surface electrodes for actuation, localized Joule heating, and thermistic temperature sensing. Furthermore, a hydrophilic pattern is formed in the multifunctional electrode to control the location of an evaporating droplet on the electrode. To demonstrate the capabilities and limitations of this technique, we performed three experiments and measured the results using MALDI-MS: (i) insulin disulfide reductions in DTT over a range of heater temperatures (22 to 70 °C) to show how reaction rates can be affected by thermal control, (ii) insulin disulfide reductions at 130 °C in DMSO to demonstrate a reaction in a high boiling point solvent, and (iii) tryptic digestions of cytochrome c at 22 and 40 °C to show that heated droplets can yield reasonably higher peptide sequence coverage than unheated droplets. Although they do not decouple the effects of changing temperatures and concentrations, these experiments verified that thermal cycling by EWOD electrodes accelerates reaction rates in liquid droplets in air.
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影响因子：
6.1
作者：
Moon, Hyejin;Wheeler, Aaron R.;Kim, Chang-Jin CJ''
通讯作者：
Kim, Chang-Jin CJ''
影响因子：
6.1
作者：
Gong, Jian;Kim, Chang-Jin (CJ)
通讯作者：
Kim, Chang-Jin (CJ)
影响因子：
2.7
作者：
Cho, SK;Moon, HJ;Kim, CJ
通讯作者：
Kim, CJ
影响因子：
7.4
作者：
Gustafsson, M;Hirschberg, D;Bergman, T
通讯作者：
Bergman, T
影响因子：
7.4
作者：
Luk, Vivienne N.;Wheeler, Aaron R.
通讯作者：
Wheeler, Aaron R.