Histological and immunohistochemical analysis of a second-look cartilage biopsy with mixed (hyaline and fibrocartilage) characteristics. Analysis of a second-look cartilage biopsy with mixed characteristics taken 10 months after Hyalograft® C Autograft implantation. (a) H & E staining. (b) Glycosaminoglycan (safranin-O staining). (c) Collagen type I (immunohistochemistry). (d) Collagen type II (immunohistochemistry). (e) Polarized light microscopy.