Park C Charles, Kazakova Irina, Kawabata Tomohisa, Spaid Michael, Chien Ring-Ling, Wada H Garrett, Satomura Shinji
Caliper Life Sciences, Mountain View, California 94043, USA.
Anal Chem. 2008 Feb 1;80(3):808-14. doi: 10.1021/ac701709n. Epub 2008 Jan 4.
This report describes a method of controlling the sensitivity and reproducibility of a microchip-based immunoassay by using isotachophoresis to preconcentrate the antigen and antibody prior to binding. Gel electrophoresis separation is coupled to the preconcentration step to separate the immunocomplex products formed. The system employs a quartz-based LabChip that automates the metering, preconcentration, reaction, separation, and detection. The system also uses a handoff mechanism that switches the immunocomplex from the stacking mode to the separation mode. We show that the handoff timing affects the data quality and repeatability of the electropherograms, and we demonstrate an automatic handoff mechanism to precisely control the signal intensity and separation of peaks of interest. In so doing, the automatic handoff mechanism also improves the reproducibility of the assay. When applied to the homogeneous liquid-phase detection of alpha-fetoprotein, a common tumor marker, the system shows a greater than 200-fold stacking of specific analytes of interest.
本报告描述了一种通过在结合前使用等速电泳对抗原和抗体进行预浓缩来控制基于微芯片的免疫测定的灵敏度和重现性的方法。凝胶电泳分离与预浓缩步骤相结合，以分离形成的免疫复合物产物。该系统采用基于石英的LabChip，可实现计量、预浓缩、反应、分离和检测的自动化。该系统还使用一种切换机制，将免疫复合物从堆积模式切换到分离模式。我们表明，切换时机影响电泳图谱的数据质量和重复性，并且我们展示了一种自动切换机制，以精确控制感兴趣峰的信号强度和分离。通过这样做，自动切换机制还提高了测定的重现性。当应用于常见肿瘤标志物甲胎蛋白的均相液相检测时，该系统显示出感兴趣的特定分析物有超过200倍的堆积。
