Reducing Spatial Heterogeneity of MALDI Samples with Marangoni Flows During Sample Preparation
Reducing Spatial Heterogeneity of MALDI Samples with Marangoni Flows During Sample Preparation
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DOI：
10.1007/s13361-016-1406-0
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发表时间：
2016-08-01
影响因子：
3.2
通讯作者：
Wang, Yi-Sheng
中科院分区：
文献类型：
--
作者：
Lai, Yin-Hung;Cai, Yi-Hong;Wang, Yi-Sheng
这项工作展示了一种方法，以准备均匀分布的分析物，以提高数据的重现性，在基质辅助激光解吸/电离（MALDI）质谱（MS）。自然空气干燥过程通常导致MALDI晶体中分析物的不希望的非均匀空间分布，并使定量分析变得困难。这项研究表明，在干燥液滴内诱导Marangoni流可以显着减少异质性问题。通过改变衬底温度来加速马兰戈尼流，以在液滴上产生温度梯度。这样的流体动力学流动进行了半经验分析。利用成像质谱技术，研究了干燥过程中分子异质性随基片温度的变化。所观察到的生物分子的异质性减少预测的马兰戈尼速度增加。与常规方法相比，在5 A摄氏度的基底上干燥液滴，同时将周围环境保持在环境条件下，通常将生物分子离子的异质性降低65%-80%。观察结果表明，在液滴干燥过程中降低基底温度是一种简单有效的手段，以减少定量应用的分析物异质性。
This work demonstrates a method to prepare homogeneous distributions of analytes to improve data reproducibility in matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS). Natural-air drying processes normally result in unwanted heterogeneous spatial distributions of analytes in MALDI crystals and make quantitative analysis difficult. This study demonstrates that inducing Marangoni flows within drying droplets can significantly reduce the heterogeneity problem. The Marangoni flows are accelerated by changing substrate temperatures to create temperature gradients across droplets. Such hydrodynamic flows are analyzed semi-empirically. Using imaging mass spectrometry, changes of heterogeneity of molecules with the change of substrate temperature during drying processes are demonstrated. The observed heterogeneities of the biomolecules reduce as predicted Marangoni velocities increase. In comparison to conventional methods, drying droplets on a 5 A degrees C substrate while keeping the surroundings at ambient conditions typically reduces the heterogeneity of biomolecular ions by 65%-80%. The observation suggests that decreasing substrate temperature during droplet drying processes is a simple and effective means to reduce analyte heterogeneity for quantitative applications.