Figure 3: Histologic staining of implants. Ossicles formed eight weeks after subcutaneous implantation of cells mixed with a collagenous matrix were stained by trichrome (a and b) or by hematoxylin and eosin (c and d). Note the greater amount of deep blue (a) and light pink (c) staining in ossicles formed by wild type cells, indicative of greater bone formation by these cells. In comparison, note the greater amount of light blue (b) and greyish-pink (d) staining in ossicles formed by Crouzon cells, indicative of greater amounts of original implanted collagen. Also note that ossicles formed by either wild type or mutant cells contain bone marrow.