ACID PHOSPHATASE 81 



improvements in the procedure, and subsequently Gomori (1946c) 

 revised his original method. His experience with the technique led 

 Gomori (1946c) to state: "For some unknown reason, the staining 

 for acid phosphatase sometimes turns out patchy, occasionally even 

 negative, when it should be positive. This seems to happen especially 

 in cases when the pieces have been exposed to the temperature of 

 the paraffin oven for more than an hour, or when the temperature of 

 the oven is over 56°C." 



The intensification of the acid phosphatase test by manganese ions 

 has been demonstrated by Moog (1943a), who found that a con- 

 centration of 0.01 M manganese sulfate gave the most satisfactory 

 results. This investigator recommends that the activator be added to 

 a clear portion of substrate medium just before use, and points out 

 that the incubation period may be approximately halved when the 

 reaction is accelerated by the manganese. Moog found that 4-5 hr. 

 was a satisfactory incubation period for tissues of the 6-day chick 

 embryo. No doubt a certain amount of trial and error must be ap- 

 plied to determine the proper incubation time for the particular 

 tissue under investigation. In a later study Moog (1944) found that 

 0.01 M ascorbic acid activated acid phosphatase and in some respects 

 appeared to have advantages over the action of manganese sulfate. 



The application of the Gomori method to grains and sprouts was 

 made by Glick and Fischer (1945b). The modification in technique 

 necessitated for these tissues will be presented. 



Gomori Revised Method for Acid Phosphatase in Animal Tissues 



SPECIAL REAGENTS 



5% Acetylcellulose (Eastman's No. 4644) in acetone. Optional. 



£% Acetic Acid. 



Ammonium Sulfide Solution. A few drops of yellow ammonium sul- 

 fide soln. to a Coplin jar of distilled water. 



Substrate Medium, pH 5. Combine 30 ml. of 1 M acetate buffer 

 (100 ml. 13.6% sodium acetate, CHsCOONa.SHsO, -f- 50 ml. 6% 

 acetic acid), 10 ml. 5% lead nitrate, and 60 ml. distilled water, 

 and add slowly while stirring 30 ml. 2% sodium glycerophosphate. 

 Shake the mixture, let stand for a few hr., and store in a refrig- 

 erator. Before use, filter a small amount and dilute it with 2-3 

 parts distilled water. 



