Testing Principle
N,N-Dimethyl-m-phenylenediamine dihydrochloride and N,N-dimethyl-p-phenylenediamine dihydrochloride are both amine salts that dissociate to carry positive charges. The diamine salts combine with sulfated acidic mucosubstances to form colored complexes. This reaction is slow and requires ferric chloride (FeCl₃) as a catalyst. On one hand, FeCl₃ oxidizes the diamine salts to form brown-black cationic chromogens, thereby accelerating the staining process. On the other hand, it lowers the pH of the staining solution to 1.4. At this pH, carboxyl groups on the tissue sections cannot bind to the diamine salts, and only sulfate groups react with the diamine salts to form purple-brown to brown-black complexes. Subsequently, Alcian Blue (pH 2.5) stains carboxylated sialomucins blue. In this way, the two main groups of acidic mucosubstances are distinctly visualized.
Stain Results
Acidic mucopolysaccharides appear blue, while other tissue cells appear light red.
Packaging Specification
Product Name | Ref # | Specification |
High Iron Diamine -Alcian Blue Stain (HID-AB) | BA4120A | 25Tests/Kit |