154 Microscopic Histochemistry 



powders had a strong catalytic effect. In 1907 Winkler^^ 

 demonstrated that the same mixture, at an alkahne reaction, 

 will stain pus cells in alcohol-fixed smears. Shortly after- 

 ward Schultze^^ adapted the stain for use on tissue sections 

 and emphasized the diagnostic value of the method in dis- 

 tinguishing myeloid from lymphoid cells. From then on, for 

 many years, the "indophenol oxidase" problem has been in 

 the focus of interest. An extremely large number of papers 

 has been published on its chemical background, its applica- 

 tion, and the interpretation of its results. The term "nadi 

 oxidase" (from a contraction of the first syllables of the two 

 reagents ) , which has gained a wide acceptance, was coined 

 by Graeff.^3 



In 1922 von Gierke^^ noticed that the distribution of the 

 reaction is not the same in fresh tissues treated with an un- 

 alkalized reagent mixture as in fixed tissues treated with an 

 alkalized one. Whereas in the first case the reaction is ex- 

 tremely widespread throughout all tissues and not particu- 

 larly intense in myeloid elements, in the second case it is 

 limited almost exclusively to the granules of myeloid leuco- 

 cytes, which stain very intensely. Furthermore, the diffuse 

 reaction ( G for Gewebe = tissue nadi reaction of Graeff ) ^^ 

 does not take place if freshly boiled distilled water is used 

 as a solvent and is readily prevented by moderate heat 

 (55° C.), by formalin, acetone, alcohol, acid, and alkali, etc. 

 The myeloid reaction ( M reaction of Graeff ) ,^^ on the other 

 hand, takes place even in oxygen-free water, is relatively 

 heat-stable (up to 80° G.), insensitive to formalin (tissues 

 kept in formalin for 6 years still give excellent reactions), to 



31. Winkler, F.: Folia haemat., 4:323, 1907. 



32. Schultze, W. H.: Beitr. z. path. Anat. u. z. allg. Path., 45:127, 1909; 

 Schultze, W. H.: Miinchen. med. Wchnschr., 56:167, 1909; Schultze, W. H.: 

 ibid., 57:2171, 1910; Schultze, W. H.: Zentralbl. f. allg. Path. u. path. 

 Anat., 28:8, 1917. 



33. Graeff, S.: Beitr. z. path. Anat. u. z. allg. Path., 70:1, 1922. 



34. Gierke, E. von: Miinchen. med. Wchnschr., 58:2315, 1911. 



35. Graeff, S.: Zentralbl. f. aUg. Path. u. path. Anat., 32:337, 1922. 



