SECTION TWO 



Technique: 



1. Fix tissues in Solution A; wash in running water and cut 

 frozen sections. 



2. Mordant the sections in Solution B for three to twenty-four 

 hours; then wash in water. 



3. Immerse in mixture of equal parts of Solutions C and D for 

 twenty to forty-five minutes. 



4. Differentiate in Solution E, examining under the microscope 

 at intervals. 



5. Wash well with distilled water. 



6. Stain with Solution F for about five minutes. 



7. Rinse quickly with 70% alcohol. 



8. Rinse with distilled water. 



9. Mount in neutral glycerine jelly. 

 Results: 



Neutral fats are stained red, whilst fatty acids are deep blue 

 black and haemoglobin, calcium and iron may also be stained. 



Note: Calcium salicylate is added to the formalin fixative to 

 convert soaps, which are sodium and potassium salts of fatty 

 acids, into insoluble calcium soaps. If it is desired to demonstrate 

 how much, if any, soap is present in addition to fatty acids, com- 

 pare stained sections of two pieces of the same material, fixing one 

 piece in Solution A and the other in ordinary 10% formalin. 



HAEMATOXYLIN (Ehrlich) - VAN GIESON STAIN 



A selective stain, for collagen and connective tissue, w^hich 

 requires less time than the Haematoxylin (Heidenhain) - 

 Van Gieson technique, although the results are not as 



satisfactory 



Solutions required: 



A. Haematoxylin (Ehrlich). 



B. Van Gieson stain (Picro Acid fuchsin). 

 Technique : 



I . Mount sections on slides ; dewax and pass through the usual 

 descending grades of alcohol to water. 



127 



