Tissue calcification can interfere with normal metabolic processes and occurs in various tissues, like bone marrow, mamma and also in tumors. The Silver Staining Kit acc. to von Kossa is used to visualize calcium deposits in histological tissue specimens. The Kit contains two ready-to-use reagents, 100 ml of a Silver nitrate solution and 100 ml of a Sodium thiosulfate solution. The kit is sufficient for up to 300 slides. As counterstain, the nuclei could be visualized with 0.1% Nuclear fast red-aluminum sulfate solution. The product is registered as IVD and CE product and can be used in diagnostics and laboratory accreditation.