In vivo, endothelial cells develop and differentiate under shear stress conditions. When starting cell-based assays with endothelial cells, you should consider the possible influence of this mechanical force on cell morphology and physiology. To bring the cells to a more physiological, in vivo-like state, they are cultured under flow for hours up to several weeks, generating more relevant results. In other words, flow conditioning is crucial for any kind of investigations using cells that are physiologically underlying flow conditions.
Investigating the influence of shear stress on endothelial cell physiology with various experimental readouts, such as immunofluorescence, western blot, qPCR, and FACS
Preparing the cell layer for subsequent functional assays, such as rolling and adhesion or transmigration assays
In a rolling and adhesion assay, leukocytes and/or platelets are perfused over a surface with a protein coating or a cell layer. Their adhesion to and their interaction with the surface can be analyzed under various conditions (e.g., after gene knockdown or drug treatment).
Investigating the adhesion of platelets and leukocytes on endothelial cells or matrix protein layers
Schulz C, et al. (2009) Novel Methods for Assessment of Platelet and Leukocyte Function Under Flow - Application of Epifluorescence and Two-Photon Microscopy in a Small Volume Flow Chamber Model. Open Biol J 2(1):130–136. read abstract
ECIS (Electric Cell-substrate Impedance Sensing) is a platform to measure morphological and physiological changes in an adherent cell layer by means of impedance. Living cells can be measured directly in the vessel without any disturbance, and without requiring any staining. The ECIS Flow Array enables the researcher to combine any type of flow assay with parallel impedance measurement.