Heparan sulfates in the terminal sac period of the lung (mouse, fetus)

Stain: fluorescence microscopy with anti-heparan sulphate antibody (a phage-display antibody, HS4E4). Heparan sulfates are linear polysaccharides that belong to the group of the glycosaminoglycans (GAGs). These GAGs are found associated with basement membranes as shown here. The sulphated saccharide domains provide numerous docking sites for protein ligands. Strong fluorescence visualizes the course of all basement membranes, especially around the bronchioles (B), subendothelially within the pulmonary artery (PA) and small branches. The lining of the air spaces (A) and capillaries within the thick septa (with non-inflatable alveoli) are also well-stained. Note negative reacting lymph vessels (Lv) (no basement membrane). GAG expression changes during tumor development.