Electrophoretic analysis of GAGs extracted from the brains of 20- and 29-week-old IDUA KO and WT mice. The GAGs extracted from mouse brains were separated via electrophoresis to identify chondroitin (CS) and dermatan (DS)-heparan (HS) sulfate, and the band of each GAG was quantified by densitometry. The total GAG amount is expressed as μg/g of dry tissue. The phenotype, age group, animal identification number (#) and percentage of CS are indicated in the figure. The arrows indicate the direction of movement of the GAG sample during gel electrophoresis.