Note: This solution should be diluted 2 : 3 with 

 distilled water before use. 



Technique: 



Note: Metallic instruments must not be used in the following 

 procedures which should be carried out in a darkened room. 

 Sections should be stained in black embryo dishes or in tubes 

 covered all round with thick brown or black paper. 



Fix in 10% formalin and embed in Celloidin or L.V.N. Sec- 

 tions are cut 15 to 25// in thickness. 



1. Immerse for twenty-four hours in ammoniated alcohol 

 (cone, ammonia i ml., alcohol 50% 99 ml.). 



2. Drain well and transfer to Solution A for six to eight hours 

 at 37° C. 



3. Drain well and transfer to Solution B in another staining 

 dish, for twenty-four to forty-eight hours at 37° C. 



4. Rinse for about five to ten seconds in 50% alcohol; then 

 reduce with Solution C for about ten minutes. 



5. Wash in several changes of distilled water; then tone in 

 Solution D for ten minutes. 



6. Wash in several changes of distilled water ; then transfer for one 

 to three minutes in Solution E, afterwards rinsing in distilled water. 



7. Immerse for three to five minutes in Solution F; then wash 

 thoroughly in distilled water. 



8. Counterstain overnight in Solution G. 



9. Wash thoroughly in distilled water then immerse in Solution 

 H for thirty minutes. 



10. Without washing transfer section to diluted Solution I for 

 one hour; then wash with 70% alcohol and differentiate the 

 counterstain in 95% alcohol. 



11. Transfer to normal butyl alcohol; clear in cedarwood oil 

 and mount. 



386 



