Oil Red O Stain

Atherosclerotic plaques were detected using Oil Red O stain for lipid content. Briefly, the aortic tree was dissected between the ascending aorta and the iliac bifurcation. After carefully removing the surrounding adipose tissue, a longitudinal incision was made along the trunk, with all the arches, including the innominate, right cephalic, and right carotid, to expose the lumen side. The opened aortic arches/tree was then mounted between 2 glass slides and fixed overnight in 10% buffered formalin solution. Samples was rinsed in isopropanol for 10 minutes before being stained with 5% of Oil red O dissolved in isopropanol for 1 hour, followed by 2 washes in PBS. Atherosclerotic plaques were imaged using Leica stereomicroscope (model M205FA) and quantitated using ImageJ software.