"One of the projects in our lab requires that we measure small currents and voltages generated by epithelial cell layers. We use epithelial cells that are the internal lining of the trachea and bronchi. These cells are grown in vitro on a membrane support that allows us to place electrodes on both sides of the cell layer, while maintaining the appropriate environment for the cell (temperature etc.). Currents are converted to analog voltage signals, amplified and then both of these signals are sent via a low-band pass filter to the VVI DAQ Plot hardware and then to an iBook or PowerBook for recording and viewing."

VVI DAQ Setup: Experiment at right, DAQ hardware center and PowerBook running VVI DAQ Plot at left

"Changes in current or voltage measured by these electrodes allow us to follow changes in ion permeation and ion transport by the cells. After measuring open circuit transepithelial voltage, we short circuit the cell layer, clamping the voltage to 0 volts and then measure changes in transepithelial current following various pharmacological treatments of the cell layer. Typically currents are about 30 microAmps per cm2 of the cell layer. The signals are sampled at 10 or 100 Hz, and recorded over several hours.

Thus VVI DAQ Plot provides a simple and inexpensive method for acquiring data, displaying the data in real-time and saving the data for analysis."

Cristina (postdoctoral fellow, left) and Vanessa (undergraduate, right) mounting epithelial cells in chamber prior to a data acquisition run. The iBook at the left shows the sensor results in real time as they run the experiment.

To learn more about Dr. Conner's research please consult: Department Of Medicine, Division Of Pulmonary & Critical Care; University Of Miami