Microsample preparation by dielectrophoresis: isolation of malaria
Microsample preparation by dielectrophoresis: isolation of malaria
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DOI：
10.1039/b110990c
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发表时间：
2002-01-01
期刊：
影响因子：
6.1
通讯作者：
Becker, FF
中科院分区：
文献类型：
--
作者：
Gascoyne, P;Mahidol, C;Becker, FF
实现医学诊断用集成微流体分析仪器的一个重要因素是前端样品制备。双电泳是一种为细胞鉴别和分离样品处理提供巨大潜力的方法，在这里，我们已经将其应用于从血液中分离疟疾感染细胞的问题。在疟疾病原体恶性疟原虫的发展过程中，受感染红细胞的质膜离子渗透性增加。当在低电导率介质中使用悬浮液挑战时，感染细胞失去内部离子，而未感染细胞保留它们。在两种微电极阵列产生的空间不均匀的行进电场中，通过介电操作来利用感染细胞和未感染细胞之间产生的介电差异。从培养物和临床标本中分离出环状或后期的寄生细胞，通过空间介电场-流分离，聚焦在螺旋电极阵列的中心，并进行鉴定和计数。介电泳方法只需要几微升血液，应该适用于生产小型、低成本的自动化设备，用于评估寄生虫浓度，可能适用于药物敏感性研究和疟疾诊断。通过简单地调整电场参数，其他表征疾病的细胞亚群，如血液中残留的癌细胞，也可以被类似地分离出来
An important enabling factor for realising integrated micro fluidic analysis instruments for medical diagnostics purposes is front-end sample preparation. Dielectrophoresis is a method that offers great potential for cell discrimination and isolation for sample processing, and here we have applied it to the problem of isolating malaria-infected cells from blood. During development of the malarial pathogen, Plasmodium falciparum, increases occur in the ionic permeability of the plasma membrane of infected erythrocytes. When challenged by suspension in a low conductivity medium, infected cells lose internal ions while uninfected cells retain them. The resultant dielectric differences between infected and uninfected cells were exploited by dielectrophoretic manipulation in spatially inhomogeneous, travelling electrical fields produced by two types of microelectrode arrays. Parasitised cells of ring form or later stage from cultures and clinical specimens were isolated by steric dielectric field-flow-fractionation, focused at the centre of a spiral electrode array, and identified and counted. The dielectrophoretic methods require only a few micro litres of blood, and should be applicable to the production of small, low-cost automated devices for assessing parasite concentrations with potential applicability to drug sensitivity studies and the diagnosis of malaria. By simple adjustment of the electrical field parameters, other cell subpopulations that characterise disease, such as residual cancer cells in blood, can be similarly isolated and