Figure 1 - Agarose gel electrophoresis of proteoglycans and glycosaminoglycans extracted from human corneas. Aliquots (5 µl) of papain-digested proteoglycans (panel A), or intact proteoglycans (PG) and glycosaminoglycans (GAG) (panel B) extracted from human corneas were submitted to agarose gel electrophoresis in 0.05 M 1,3-diaminopropane acetate buffer, pH 9.0, at 5 V/cm for 1 h. The proteoglycans and glycosaminoglycans were fixed in the gel by 0.1% cetyltrimethylammonium bromide and stained with toluidine blue, as previously described (15). The ³⁵S-labeled compounds were observed by radioautography. Decorin (a dermatan sulfate proteoglycan) and keratan sulfate were also identified by immunoblotting stained with an anti-decorin polyclonal antibody and MST1 (an anti-keratan sulfate monoclonal antibody). M: Mixture of standard glycosaminoglycans containing chondroitin sulfate (CS), dermatan sulfate (DS), keratan sulfate (KS), and heparan sulfate (HS).