MEDICAL AND BIOLOGICAL STAINING TECHNIQUES 



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. 



The following fixatives are recommended: 

 (I). Chloral hydrate . . . . • • 25 gm. 

 Alcohol 50% . . . . . . 100 ml. 



(II). Formalin, undiluted (i.e. Form- 

 aldehyde 40%). . . . . . . 20 ml. 



Alcohol 95% 80 ml. 



(III). Ammonium bromide . . . . 2 gm. 



Formalin, undiluted (i.e. Form- 

 aldehyde 40% . . . . . . 15 ml. 



(IV). 95% or Absolute Alcohol 



(V). Bouin's fluid. 



Solutions, I, II, III and IV are satisfactory for Central Nervous 

 System and nerve trunks. 



Solution I has been used with satisfaction for striated muscle 

 tissue. 



Solution II is suitable for gland and smooth muscle tissue. 



Solution V for gland and smooth muscle tissues and for embryos. 



Tissues may also be fixed in 10% formalin with good results, 

 but an excessive staining of connective tissue has been observed 

 when this fixative has been employed. 



Solutions required: 



A. Picric acid, saturated aqueous 

 Mercuric cyanide . . 



B. Silver nitrate 1% aqueous 

 Urea . . 

 Solution A . . 



C. Hydroquinone 

 Urea . . 

 Distilled water 

 Sodium sulphite, anhydrous 



50 ml. 

 0-5 gm. 



100 ml. 



25 gm. 

 3 drops 



2gm. 



25 gm. 

 100 ml. 

 10 gm. 



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