Center for Bio/Molecular Science & Engineering, Naval Research Laboratory, Washington, DC 20375, USA.
Biosens Bioelectron. 2013 Feb 15;40(1):10-6. doi: 10.1016/j.bios.2012.08.015. Epub 2012 Aug 16.
A spinning magnetic trap (MagTrap) for automated sample processing was integrated with a microflow cytometer capable of simultaneously detecting multiple targets to provide an automated sample-to-answer diagnosis in 40 min. After target capture on fluorescently coded magnetic microspheres, the magnetic trap automatically concentrated the fluorescently coded microspheres, separated the captured target from the sample matrix, and exposed the bound target sequentially to biotinylated tracer molecules and streptavidin-labeled phycoerythrin. The concentrated microspheres were then hydrodynamically focused in a microflow cytometer capable of 4-color analysis (two wavelengths for microsphere identification, one for light scatter to discriminate single microspheres and one for phycoerythrin bound to the target). A three-fold decrease in sample preparation time and an improved detection limit, independent of target preconcentration, was demonstrated for detection of Escherichia coli 0157:H7 using the MagTrap as compared to manual processing. Simultaneous analysis of positive and negative controls, along with the assay reagents specific for the target, was used to obtain dose-response curves, demonstrating the potential for quantification of pathogen load in buffer and serum.
一种用于自动化样品处理的旋转磁捕获（MagTrap）与能够同时检测多个靶标的微流控细胞仪集成在一起，可在 40 分钟内提供自动化的“从样品到答案”诊断。在荧光编码的磁性微球上捕获靶标后，磁捕获自动浓缩荧光编码的微球，将捕获的靶标与样品基质分离，并依次将结合的靶标暴露于生物素化示踪分子和链霉亲和素标记的藻红蛋白。然后将浓缩的微球在能够进行 4 色分析的微流控细胞仪中进行水力聚焦（两个波长用于微球识别，一个用于光散射以区分单个微球，一个用于与靶标结合的藻红蛋白）。与手动处理相比，MagTrap 可将样品制备时间缩短三倍，并提高检测限，而无需进行靶标预浓缩。使用 MagTrap 检测大肠杆菌 0157:H7 时，还可以同时分析阳性和阴性对照以及针对靶标的检测试剂，以获得剂量反应曲线，从而证明了在缓冲液和血清中定量病原体负荷的潜力。
