Stains & CD markers

Last author update: 1 October 2013
Last staff update: 21 June 2021

Copyright: 2003-2023,, Inc.

PubMed Search: von Kossa methodAlizarin red SAzan stain

Nat Pernick, M.D.
Page views in 2022: 1,986
Page views in 2023 to date: 987
Cite this page: Pernick N. Calcium. website. Accessed June 4th, 2023.
Definition / general
  • With routine staining, calcium forms a blue-black lake with hematoxylin, usually with sharp edges
  • von Kossa method: silver is substituted for calcium in calcium salts; light or a photographic developer turns the silver black; only stains calcium bound to an anion such as phosphate or carbonate; most useful when large amounts of phosphates and carbonates are present, as with bone
  • Alizarin red S forms an orange-red lake with calcium at a pH of 4.2; works best with small amounts of calcium such as in Michaelis-Gutman bodies; this method is used on Dupont ACA analyzer to measure serum calcium photometrically
  • Azan stain used to distinguish osteoid from mineralized bone.
Microscopic (histologic) images

Images hosted on other servers:

Malakoplakia of bladder (von Kossa calcium stain)

Back to top
Image 01 Image 02