[Selective demonstration of amloid deposits and methodical possibilities for the analysis of ultrastructural differences].

In preparations stained by congo-rot and covered with arabic gumm amyloid deposits reveal intensive, positive bi refringement, collagen is isotrop, or shows a mild bi refringement. This method is most suitable for selective optical demonstration of amyloid deposits. On the base of investigation of ultrastructural stability of amyloid deposits (resistency to performiat and induced proteolysis) two types of them may be distinguished: I. amyloid deposits of labile structure (generalized, secondary amyloidosis) and 2. amyloid deposits of stabile structure (generalized primary amyloidosis, local and senile amyloid deposits).