BIOS-Lab on a Chip Group, MESA+ Institute of Nanotechnology, TechMed Centre and Max Planck Center for Complex Fluid Dynamics, University of Twente, Enschede, Overijssel, The Netherlands.
Department of Physical and Macromolecular Chemistry, Charles University in Prague, Prague, Czech Republic.
Electrophoresis. 2019 Mar;40(5):756-765. doi: 10.1002/elps.201800393. Epub 2018 Dec 20.
Point-of-care systems based on microchip capillary electrophoresis require single-use, disposable microchips prefilled with all necessary solutions so an untrained operator only needs to apply the sample and perform the analysis. While microchip fabrication can be (and has been) standardized, some manufacturing differences between microchips are unavoidable. To improve analyte precision without increasing device costs or introducing additional error sources, we recently proposed the use of integrated internal standards (ISTDs): ions added to the BGE in small concentrations which form system peaks in the electropherogram that can be used as a measurement reference. Here, we further expand this initial proof-of-principle test to study a clinically-relevant application of K ion concentrations in human blood; however, using a mock blood solution instead of real samples to avoid interference from other obstacles (e.g. cell lysis). Cs as an integrated ISTD improves repeatability of K ion migration times from 6.97% to 0.89% and the linear calibration correlation coefficient (R ) for K quantification from 0.851 to 0.967. Peak area repeatability improves from 11.6-13.3% to 4.75-5.04% at each K concentration above the LOQ. These results further validate the feasibility of using integrated ISTDs to improve imprecision in disposable microchip CE devices by demonstrating their application for physiological samples.
基于微芯片毛细管电泳的即时检测系统需要一次性、即用型的微芯片，其中预先填充了所有必要的溶液，因此未经培训的操作人员只需应用样品并进行分析。虽然微芯片制造可以（并且已经）标准化，但微芯片之间仍存在一些不可避免的制造差异。为了在不增加设备成本或引入额外误差源的情况下提高分析物精度，我们最近提出使用集成内部标准（ISTD）：以小浓度添加到 BGE 中的离子在电泳图中形成系统峰，可作为测量参考。在这里，我们进一步扩展了这个初始原理验证测试，以研究人类血液中 K 离子浓度的临床相关应用；然而，我们使用模拟血液溶液而不是真实样本来避免其他障碍物（例如细胞裂解）的干扰。Cs 作为集成 ISTD，将 K 离子迁移时间的重复性从 6.97%提高到 0.89%，K 定量的线性校准相关系数（R）从 0.851 提高到 0.967。在 LOQ 以上的每个 K 浓度下，峰面积重复性从 11.6-13.3%提高到 4.75-5.04%。这些结果进一步验证了使用集成 ISTD 通过演示其在生理样品中的应用来提高一次性微芯片 CE 设备不精密度的可行性。
