Experience with the sodium sulphate-Alcian Blue stain for amyloid in cardiac pathology.

The sodium sulphate-Alcian Blue (SAB) method, which stains amyloid green, was evaluated in 220 hearts from elderly patients. The technique proved superior to the Congo red, crystal violet, and thioflavine T methods used either singly or as a battery for the demonstration of cardiac amyloid. Amyloid was easily identified under the X3 objective, even in small amounts. A few non-amyloid components stained varying shades of green but were easily distinguished on morphological grounds. No false positive or equivocal reactions occurred, and in particular elastic laminae and paravascular connective tissue were not tinctorially confused with amyloid. The SAB stain is technically simple and consistently reproducible, and no special light source is required for examination. An additional advantage in cardiac pathology is the simultaneous demonstration of any fibrosis, basophilic myofibre degeneration, tissue mast cells and mucoid degeneration of valves present.