5.7. Immunofluorescence

HUVECs were fixed with 4% paraformaldehyde for 15 min. After a 20 min permeabilization with 0.1% Triton X-100 and 1 h of blocking with 10% goat serum, an anti-intercellular adhesion molecule1 (ICAM1, #ab2213, Abcam) antibody diluted at a ratio of 1:100 was injected into the chip channel and then incubated at 4 °C overnight. After washing, Alexa Fluor 546 goat anti-mouse antibody solution diluted in 1/200 was incubated at 37 °C in the dark for 2 h. HUVECs were also stained with 100 μL of Alexa Fluor 488-conjugated phalloidin (#P5285, Sigma-Aldrich) solution for 1 h in the dark at room temperature followed by infusing DAPI (#C1005, Beyotime) solution for 2 min. After washing, images were captured using a microscope with a CCD camera.