Researchers in the School of Biomedical Engineering at Drexel University have developed a flow chamber and method for detecting the presence of one or more cell-produced analytes under flow conditions.  The parallel-plate flow chamber has two components separated by a permeable membrane, with one compartment containing the cells that are subjected to the flow field.  The other compartment has a recording electrode to allow detection of cell-produced analytes and is isolated from the effects of flow.

The researchers have demonstrated the feasibility of this system by directly measuring nitric oxide (NO) in real time from endothelial cells across a range of shear stress applied.  NO is present in the micromolar to nanomolar range and reacts rapidly with molecular oxygen for a short half-life of 2-30 seconds; the low concentration and short-lived nature of NO present technical challenges for direct measurement from cells.  NO production from the endothelium is involved in vascular tone, and the level has implications for atherosclerosis and hypertension.