Figure 1. Type I collagen fibrils from rat tail prepared in vitro without (A) and with (B) chondroitin sulfate (10 mg/100 mg collagen). The CS added was chemically oversulfated to a sulfation degree of 3 sulfate groups per disaccharide. The resulting fibrils are finer than collagen fibrils without added CS. Images 5 × 5 µm, AFM tapping mode (the authors thank Dr. S. Heinemann for the AFM-investigation).