STAINING, PRACTICAL AND THEORETICAL 



aqueous solution drop by drop until the solution be- 

 comes yellowish-blue in colour and the a-Naphthol is 

 still not completely dissolved. 



B. Cold tap water . . . . . . lOO ml. 



*Dimethyl-p-phenylenediamine 



base . . . . . . . . 0-5 gm. 



Place the water in a clean amber bottle, open the ampoule 

 by filing a groove at one end then breaking in the usual 

 manner. Tip the contents of the ampoule into the bottle; 

 then replace the stopper and allow the bottle to stand, with 

 occasional shaking, for twenty-four hours. Care should be 

 taken that the Dimethyl-p-phenylenediamine base does not 

 come into contact with the body. 



This solution deteriorates after three or four weeks. 



C. Gram's iodine solution. 



D. Carmalum, 



Technique: 



1. Thin pieces of fresh tissue (not more than 3 mm. thick) are 

 fixed for three to five hours in formalin-saline solution. 



2. Make frozen sections and collect them in distilled water. 



3. Immerse in a mixture consisting of equal volumes of Solu- 

 tions A and B {Note: This mixture must be made and filtered 

 immediately before use) for about five minutes until the sections 

 turn blue. 



4. Rinse sections rapidly in distilled water. 



5. Immerse in Gram's iodine solution until the sections turn 

 brown. 



6. Transfer to distilled water to which two drops of lithium car- 

 bonate 0-5% aqueous have been added for each 100 ml. of distilled 

 water, for a quarter to twenty-four hours until the sections have 

 regained their blue colour. 



7. Wash in distilled water then counterstain in carmalum for 

 two to five minutes. 



8. Mount in glycerine jelly or Apathy's medium or in Aqua- 

 mount. 



* This should be purchased in a sealed ampoule. 



