The use of primary hepatocyte cultures as in vitro models for studying xenobiotic metabolism and toxicity is limited by the loss of liver-specific differentiated functions with time in culture. This study investigates the effect of incorporating 20% chondroitin-6-sulphate (Ch6SO4), a glycosaminoglycan (GAG), into collagen gels (0.3% w/v), and crosslinking the gels with either 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDAC) or 1,6-diaminohexane (DAH) on the expression and total activity of glutathione-S-transferases (GSTs) in hepatocytes cultured for 7 days. GSTs are a family of isoenzymes. The main isoenzyme in the male rat liver is the alpha form (which exists as several subunits (Ya and Yc2 were measured here)). The pi form (subunit Yf) is not normally present in liver, but is expressed in conditions where the liver cells are de-differentiated.