Safranin O stained meniscus tissue from different species, all scale bars 3 mm. A) Bovine meniscus with almost no prominent Safranin O staining. Only two localized regions (*) show some minor stain deposits. B) Ovine tissue, prominent red Safranin O staining at the inner third of the meniscus is visible. C) Human meniscus with two third of the inner tissue regions labeling red with Safranin O stain. Note the similarity in shape between ovine and human meniscus cross-sections. D) The porcine meniscus is labeling completely positive with Safranin O stain.