SPECTROSCOPY, IMAGING, OTHER TECHNIQUES |
Micro Magnetic Tweezers for Nanomanipulation inside Live Cells
Anthony H.B. de Vries 1, Bea E Krenn 2, Roel van Driel 2 and Johannes Kanger 1*
1 University of Twente
2 University of Amsterdam
* To whom correspondence should be addressed. E-mail: j.s.kanger{at}tnw.utwente.nl.
Submitted on August 31, 2004
Revised on October 10, 2004
Accepted on 9 November 2004
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Abstract |
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This paper reports the design, realization and characterization of a multi-pole magnetic tweezers that enables us to maneuver small magnetic probes inside living cells. So far magnetic tweezers can be divided in two categories: (I) tweezers that allow the exertion of high forces but consisting of only one or two poles and therefore capable of only exerting forces in one direction; and (II) tweezers that consist of multiple poles allow exertion of forces in multiple directions but at very low forces. The magnetic tweezers described here combines both aspects in a single apparatus: high forces in a controllable direction. To this end micron scale magnetic structures are fabricated using cleanroom technologies. With these tweezers magnetic flux gradients of B = 8x103 Tm-1 can be achieved over the dimensions of a single cell. This allows exertion of forces upto 12 pN on paramagnetic probes with a diameter of 350 nm enabling us to maneuver them through the cytoplasm of a living cell. It is expected that with the current tweezers pN forces can be exerted on beads as small as 100 nm.
Key Words:
cell biology, cytoskeleton, micromechanics, rheology
