STAINING, PRACTICAL AND THEORETICAL 



E. Lead nitrate, 2% aqueous 



F. Ammonium sulphide, cone. sol. i volume 

 Distilled water . . . . • • 5 volumes 



Technique: 



Note: Gomori states that celloidin protection is useful 

 but only permissible in the case of saturated substrates; the 

 unsaturated ones penetrate the celloidin membrane very poorly. 



1. Material should be fixed in 10% formalin at 4° C, and the 

 frozen sections cut as thin as possible. Alternatively, material may 

 be fixed in acetone at 4°C. and embedded in celloidin-paraffinwax. 



2. Fix frozen sections to slides, without the use of glycerine 

 albumen, and leave to dry thoroughly in the atmosphere at room 

 temperature. If sections of double embedded material are used, 

 fix to slides with glycerine albumen and allow to dry thoroughly 

 in the air at room temperature. 



3. Incubate the slides at 37° C. in reagent D. 



4. Rinse the slides in distilled water. 



5. Immerse in reagent E for ten minutes at 45° C. 



6. Wash in repeated changes of distilled water for five to ten 

 minutes. 



7. Immerse in reagent F for about five minutes. 



8. Wash in running water for five to ten minutes. 



9. Counterstain as desired. 



ID. Wash thoroughly in water and mount in Aquamount or in 

 glycerine jelly; or dehydrate, clear, and mount in D.P.X. or 

 Clearmount. 



Results: 



Lipases are indicated by a dark brown deposit. 

 Reference: Gomori, G. (1952), pp. 203-206. 



UREA SILVER NITRATE 

 For nerve fibres and nerve endings 



Note: In this technique, nerve fibres and nerve endings of 

 the peripheral and central nervous system are preferentially 

 stained. 



Applied to paraffin sections on slides, the technique gives rapid 

 and constant results, and eliminates the necessity of gold toning. 



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