Abstract
Saponification reverses the methylation blockade of cartilage and mast cell basophilia demonstrated by azure A above pH 3-4, but fails to do so at pH levels below this range. Saponification of oxidized hair cortex restores the methylation blocked basophilia demonstrable at pH 2 or higher. Mouse amyloid is characterized by a weak basophilia which is relatively resistant to methylation.
The results are interpreted as indicating that methylation hydrolyzes the sulfate esters and esterifies other acid groupings in tissue sections.