cell culture with less contribution from the electrode polarization impedance can be studied ( 34 , 35 ). This combined electrode configuration can be used to provide structural information during the growth and differentiation process of the stem cells in a nondestructive way ( 36 , 37 ). Moreover, by benefitting from the combinations of two, three and four electrode configurations, more electrode pairs with various spatial distributions can be applied to study the spatial distribution of cells in a 3D cell construct. It should be noted that factors such as
Humayra Ferdous, Tanvir Noor Baig and K. Siddique-e Rabbani
electrode probe used. Wet cotton wool is inserted into cylindrical recesses touching the metallic electrode inside an insulated cylindrical structure. Each electrode has a spring-loaded stem allowing perpendicular movement in order to ensure good connections at curved body surfaces.
The handheld electrode probe, seen from the electrode side. Wet cotton wool is inserted into recesses touching the metallic electrode inside. The stems of the electrodes are spring-loaded to ensure good contact at curved body surfaces.
Body mapping Matrix
Colin Chung, Martin Waterfall, Steve Pells, Anoop Menachery, Stewart Smith and Ronald Pethig
in cell state during DEP experiments than through determination of fx01 alone. This could be of particular importance for DEP studies and manipulations of stem cells [ 18 ].
The authors thank Dr Martin Reekie for helpful discussions. This work was supported by a Wolfson Microelectronics Scholarship awarded to C.C., and the Edinburgh Research Partnership in Engineering and Mathematics (ERPem).
Calculating the DEP cross-over frequency using equation 2 requires both the effective permittivity and effective conductivity
O. Wahlsten, J. B. Skiba, I. R. S. Makin and S. P. Apell
electrical fields on bacterial cultures [ 11 ].
It should be pointed out that we are focusing on devices where possible field strengths are two orders of magnitude less than the 100 kV/m, which is the typical field strength of electroporation and electrofusion on a cellular level, and the investigated devices in this paper have DC characteristics. This regime has been of interest since the early 80’s [ 12 , 13 ] stimulated by the early work of Becker summarized in [ 1 ]. The original research stems from the pioneering frog studies by Volta more than two centuries ago
the right hemisphere). Important points in the model are marked by circles. The potentials at these points can be obtained from the RC-model at the bottom, which permits calculation of the induced dipole moment and transmembrane potential. From the existence of Maxwell's equivalent body, it follows that electric measurements (detecting the induced dipole moment) do not allow one to distinguish whether frequency-dependent object properties stem from internal structures or from the frequency-dependent properties of the media of which the object is composed.
Kathrin Badstübner, Marco Stubbe, Thomas Kröger, Eilhard Mix and Jan Gimsa
parameters in calibration solution with numerical cell constants. The capacitances that correspond to R cal were calculated from the experimental cell constants with equation (2) .
R cal ± SEM [Ω]
σ [Sm -1 ]
γ ± SEM [μm]
C cal ± SEM [pF]
17,544 ± 1,933
460 ± 65
0.33 ± 0.05
7,631 ± 78
1049 ± 13
0.74 ± 0.01
Clearly, the largest contribution to ( C Add ) stemmed from the immersed parts of the
Tushar Kanti Bera, Nagaraju Jampana and Gilles Lubineau
-electrode-method-based EIS using a QuadTech7600 impedance analyzer with a 1 mA constant sinusoidal applied current. The impedance variations in cucumber ( Cucumis sativus ), carrot ( Daucus carota ), pumpkin ( Cucurbita mixta ), bottle gourd ( Lagenaria vulgaris ), banana cortex or pseudo stem of the banana tree ( Musa acuminata ), potato ( Solanum tuberosum ), tomato ( Lycopersicon Esculentum L ), bringle ( Solanum melongena ), mango ( Mangifera indica ), apple ( Malus domestica ) and orange ( Citrus sinensis ) were studied to measure the Z b and θ b at 100 discrete frequency points