|Infobox on Alizarin|
|Example of Alizarin|
|Origin||Originally Central Asia and Egypt|
|Stowage factor (in m3/t)||Density 1,54 g/cm3|
|Humidity / moisture||-|
|Risk factors||See text|
Alizarin is an organic compound that has been used throughout history as a prominent red dye, principally for dyeing textile fabrics. Historically it was derived from the roots of plants of the madder genus. In 1869, it became the first natural pigment to be duplicated synthetically.
Alizarin is the main ingredient for the manufacture of the madder lake pigments known to painters as Rose madder and Alizarin crimson. Alizarin in the commonest usage of the term has a deep red color, but the term is also part of the name for several related non-red dyes, such as Alizarine Cyanine Green and Alizarine Brilliant Blue. A notable use of alizarin in modern times is as a staining agent in biological research because it stains free calcium and certain calcium compounds a red or light purple color. Alizarin continues to be used commercially as a red textile dye, but to a lesser extent than 100 years ago.
Alizarin Red is used in a biochemical assay to determine, quantitatively by colorimetry, the presence of calcific deposition by cells of an osteogenic lineage. As such it is an early stage of matrix mineralization, a crucial step towards the formation of calcified extracellular matrix associated with true bone.
Alizarin's abilities as a biological stain were first noted in 1567, when it was observed that when fed to animals, it stained their teeth and bones red. The chemical is now commonly used in medical studies involving calcium. Free (ionic) calcium forms precipitates with alizarin, and tissue block containing calcium stain red immediately when immersed in alizarin. Thus, both pure calcium and calcium in bones and other tissues can be stained. The process of staining calcium with alizarin works best when conducted in basic solution.
In clinical practice, it is used to stain synovial fluid to assess for basic calcium phosphate crystals. Alizarin has also been used in studies involving bone growth, osteoporosis, bone marrow, calcium deposits in the vascular system, cellular signaling, gene expression, tissue engineering, and mesenchymal stem cells.
In geology, it is used as a stain to indicate the calcium carbonate minerals, calcite and aragonite.
Shipped in barrels, kegs or drums.
May be subject to loss of weight due to seepage. Insoluble in cold water.