ACID AND OTHER PHOSPHATASES 85 



4. Place in ammonium sulfide soln. for 2-3 min. 



5. Wash with several changes of distilled water, dehydrate in 

 95% alcohol for 2-3 min., and follow by 5 min. in absolute alcohol. 



6. Clear in oil of thyme for 3-4 min., treat with three changes of 

 xylol. (Treatment with xylol should be brief since the black 

 precipitate indicating enzyme action is soluble to some degree in 

 xylol.) Mount in balsam. 



Result. The phosphatase activity is visualized as a brown or 

 black precipitate. 



OTHER PHOSPHATASES 



Various investigators have studied the histological distribution 

 of phosphatases capable of hydrolyzing substrates other than those 

 commonly employed for the acid and alkaline phosphatases. This 

 work has been accomplished by simply substituting the new 

 substrates for the glycerophosphate usually used, and employing 

 the standard phosphatase procedures. 



Wolf, Kabat, and Newman ( 1943) used ribonucleic acid and 

 glucose- 1-phosphate as additional substrates in their work on acid 

 phosphatase distributions, particularly in the human and guinea 

 pig nervous systems. Glick and. Fischer (1945b, 1946a) employed 

 adenosine triphosphate, thiamine pyrophosphate, and glucose- 1- 

 phosphate in a study of the enzyme distributions in wheat and parts 

 of the germinated grain. In investigations on the mouse duodenum, 

 Dempsey and Deane ( 1946) , and in work on the thyroids of various 

 species, Dempsey and Singer (1946), utilized adenylic acid, ribo- 

 nucleic acid, glucose- 1-phosphate, fructose diphosphate, and lecithin 

 as their additional substrates. Krugelis (1946) studied the phos- 

 phatases in the larval salivary glands of Drosophila and in various 

 organs of the mouse using adenylic acid, guanylic acid, cytidylic 

 acid, ribonucleic acid, desoxyribonucleic acid, and a depolymerized 

 form of the latter, as substrates. 



With the staining technique it is difficult at times to define the 

 specificities of the various phosphatases which act on the different 

 substrates. For instance, both alkaline phosphatase and adenyl- 

 pyrophosphatase (adenosinetriphosphatase), which are known to 

 be two distinct enzymes, can act on adenosine triphosphate, as 



