Mediated Mechanism Of The Electrophoresis Cell Dielectric Response Law, Separation And Heavy Metal Cytotoxicity

Dielectrophoresis is a new technique which can be used in separating and analyzing neutral particles. It had been used extensively in research of biology, chemistry, medical science, environmental science and even nanometer technique by the late 20th Century.This paper reports that the dielectrophoretic technique's evelopment and its application in many fields, and also introduces the review of its progress and advantages in cell research in detail.Dielectrophoresis is a technique by which neutral particles can be guided by non-uniform AC fields to induce spatial movement when they are exposed to a non-uniform electric field in a suspension medium. The technique of dielectrophoresis for separating cells has many advantages. In operation, no antibody be used, no harm to cells takes place. And it can be used vividly and the conditions can be adjusted easily. The all system can be controlled automatically and can be used repeatedly. In addition, the technique can be combined with other methods to get better result of separation and examination. Therefore traditional separation technique can be instead by dielectrophoretic technique completely.In this study, we fabricated a group of DEP microchips of electrode arrays with different shapes and built up a DEP research micro-system, with which we investigated DEP responses of different cells and achieved separation between different cell types in the same chip. I get the results as following:1. The phenomenon of experiment: positive DEP, negative DEP, linear motion, fusion and rotation of cells were observed in the experiment. Three parameters including buffer conductivity, applied voltage and frequency were chosen to determine the optimum conditions. By adjusting those parameters, I determined the conditions of positive DEP, negative DEP and the cross-over conductivity scope.2. The impact analysis on physical parameter: The force depends on a number of conditions such as the arrangement of the electrode, the frequency of the electric field and the resulting electric field distribution as well as dielectric properties of the particles and the surrounding medium. By experiments, I get a series of regularities about DEP responses with time, applied voltage, electric-field intensity, buffer conductivity, frequency, the properties of cells and the shape of electrodes.3. The separation of cells: Different cells can be separated and manipulated on the basis of their difference in these parameters. Such as separation between the yeast cells and the chicken blood cells, the deformed cells and the normal cells, and the cells poisoned by copper ions and the normal cells.4. The DEP responses of cells poisoned by heavy metal ion solution: the cross-over conductivity scope of the chicken blood cells poisoned by heavy metal ion solution changed obviously with the time and the heavy metal ion solution's density.