Cells Under Flow
The ECIS Z and ECIS Z Theta instruments can be equipped with a flow option (ECIS p-Flow Peristaltic Pump) specifically designed for researchers who wish to employ ECIS impedance measurements to study the behavior of cells under flow conditions. The ECIS flow arrays provide eight independent measuring electrodes on the floor of a channel 0.5 cm wide and 5 cm long with a height of 0.4 mm (with other heights available).
Flow can be programmed from slow rates to perfuse the cells with medium to high rates yielding shear stress similar to that experienced by endothelial cells in vivo. In addition to steady laminar flow, the flow programming also includes the ability to generate pulsed flows of different periods and with varying flow rates
In addition to the peristaltic pump and software, the system includes all tubing and fittings, medium reservoir and flow damper. Although only one or two pumps are required for many ECIS applications, multiple pumps can be connected together via a USB hub, all controlled independently by the software. The ECIS Z and ECIS Z Theta instruments can also be equipped with an elevated field module which allows for electroporation and/ or cell migration measurements, via automated wound-healing assays, under flow conditions.
Cells are cultured on the electrode plate and culture media is pumped over the electrode plate. Cell activity is monitored by the ECIS instrumentation.
Bovine aortic endothelial cells were grown to confluence on the ECIS array and introduced into the flow chamber. The resistive portion of the impedance (normalized to the starting value) was monitored with an ECIS system and is presented as a function of time. Flow is turned on and off as indicated by the arrows. Data was collected every minute and error bars are shown every 15 minutes.*
Shikataa, Y., Riosa, A., Kawkitinaronga, K., DePaolab, N., Garciaa, J.G.N., Birukov, K.G., "Differential effects of shear stress and cyclic stretch on focal adhesion remodeling, site-specific FAK phosphorylation, and small GTPases in human lung endothelial cells." Experimental Cell Research Volume 304, Issue 1, 40-49 (2005).
*DePaola, N., Phelps, J.E., Florez, L., Keese, C.R., Giaever,I., Minnear, F.L., and Vincent, P. "Electrical Impedance of Cultured Endothelium Under Fluid Flow.", Annals of Biomedical Engineering 29, pp. 1-9 (2001)
Phelps, J.E., and DePaola, N. "Spatial Variation in Endothelial Barrier Function in Disturbed Flows inVitro." American Journal of Physiology: Heart and Circulatory Physiology, 278: H469-H476, (2000).