( ¹Department of Biomedical Engineering, Purdue University, West Lafayette, IN 47906, USA;
²School of Mechanical Engineering, Purdue University, West Lafayette, IN 47906, USA;
³Department of Biomedical Engineering, Zhejiang University, Hangzhou 310027, China )

Abstract To establish a stable and realª²time method to detect the production of intracellular nitric oxide (NO) of endothelial cells under different shear stresses. After the cultured endothelial cells were loaded with DAF-FM, the relative NO production was determined by fluorescence intensity, which was detected using Zeiss Axioskop 2 fluorescence microscope and ICCD-camera. The fluorescence of DAF-FM can reflect NO production. Shear stress can induce a dose-dependent increase of NO production, and the increase can be totally inhibited by L-NAME and partly inhibited by Ca²⁺-free buffer. The method can be used to detect the change of NO production in real time, and it can also be used to study the mechanism related to NO increase induced by shear stress.