title: Use of alizarin red S for histochemical staining of Ca2+ in the mouse; some parameters of the chemical reaction in vitro.
abstract: Alizarin red S (ARS) is used for histological characterization of calcium. In order to improve the conditions of the use of the dye on biological materials, the chemical reaction between ARS and Ca2+ is studied in vitro. In aqueous solution ARS and Ca2+ ions precipitate to form brick-red deposits. For precipitation to occur a neutral pH (4 less than pH less than 8) is required; the stoichiometric ratio is 1:1. ARS reacts with calcium via its sulfonate and hydroxyl groups. The apparent solubility product is around 10(-7) Na+ and K+ ions do not interfere with equilibrium of the precipitation reaction but Mg2+ and soluble proteins such as bovine serum albumin react with ARS and form soluble complexes which can lead to a decrease in the ARS quantity available to react with the calcium ions.
mesh_terms: D000818:Animals; D000880:Anthraquinones; D002118:Calcium / Q000032:analysis* / Q000494:pharmacology; D002850:Chromatography, Gel; D004586:Electrophoresis; D006651:Histocytochemistry; D066298:In Vitro Techniques; D008274:Magnesium / Q000494:pharmacology; D051379:Mice; D011188:Potassium / Q000494:pharmacology; D011506:Proteins / Q000494:pharmacology; D012964:Sodium / Q000494:pharmacology; D012996:Solutions
chemical_list: D000880:Anthraquinones; D011506:Proteins; D012996:Solutions; C004468:Alizarin Red S; D012964:Sodium; D008274:Magnesium; D011188:Potassium; D002118:Calcium