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Biomed Microdevices (2006) 8:227230
DOI 10.1007/s10544-006-8170-zDielectrophoresis tweezers for single cell manipulationT. P. Hunt R. M. WesterveltSpringer Science + Business Media, LLC 2006Abstract Positioning single cells is of utmost importance
in areas of biomedical research as diverse as in vitro fertilization, cell-cell interaction, cell adhesion, embryology,
microbiology, stem cell research, and single cell transfection. Here we describe dielectrophoretic tweezers, a sharp
glass tip with electrodes on either side, capable of trapping
single cells with electric fields. Mounted on a micromanipulator, dielectrophoresis tweezers can position a single cell in
three dimensions, holding the cell against fluid flow of hundreds of microns per second with more than 10 pN of force.
We model the electric field produced by the tweezers and
the field produced by coaxial microelectrodes. We show that
cells are trapped without harm while they divide in the trap.
In addition, dielectrophoretic tweezers offer the possibility
for trapping, electroporating, and microinjecting a single cell
with one probe.Keywords Dielectrophoresis . Single cell manipulation .
Tweezers . Single cell electroporation.As biologists struggle to understand and manipulate living systems, they increasingly turn to single cell analysis
(Brehm-Stecher and Johnson, 2004). With the advance of
miniaturization, it is now possible to perform mRNA analysis on a single cell (Eberwine, 2001), transfect a singleT. P. Hunt ([envelopeback]) . R. M. Westervelt
Department of Physics, Harvard University, Cambridge, MA
02138, USAe-mail: tomhunt@physics.harvard.eduR. M. WesterveltDivision of Applied Sciences, Harvard University, Cambridge,
MA 02138, USAPublished online: 19 May 2006Ccell to change its gene expression, observe how one cell differentiates, or study how two individual cells interact. The
quantum of biology is the cell, and biologists strive to reach
into that world. For over one hundred years, the standard
technique for single cell manipulation has been to grasp a
cell with suction through a hollow glass micropipette tip
(Barber, 1904). This manipulation process requires a very
skilled operator and can easily damage the cell membrane
or cytoskeleton (Fleming and King, 2004). Optical tweezers
are an alternative (Ashkin et al., 1987), requiring intricate
optics and producing limited manipulation force. Microactuators for physically holding cells (Chronis and Lee, 2004)
are possible to build but have not been widely adopted. Local magnetic fields can be used to move cells (Gosse and
Croquette, 2002; Lee et al., 2004) if...