Quantification of the endothelial surface glycocalyx on rat and mouse blood vessels

► The surface glycocalyx layer (SGL) in the rat and mouse blood vessels was quantified. ► In vivo immunolabeling and laser scanning confocal microscopy were used. ► ~ 1 μm thick SGL on capillaries and post-capillary venules but no SGL on arterioles. ► ~ 2 μm thick SGL is uniformly distributed on aortas. ► Our method overcomes the dehydration artifacts and specifies the SGL component.