SECTION TWO 



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 . . 50 ml. 

 Mercuric cyanide . . . . . . 0-5 gm. 



B. Silver nitrate 1% aqueous . . . . 100 ml. 



Urea . . . . . . . . . . 25 gm. 



Solution A . . . . . . • • 3 drops 



C. Hydroquinone . . . . . . 2 gm. 



Urea . . . . . . . . • . 25 gm. 



Distilled water . . . . . . 100 ml. 



Sodium sulphite, anhydrous . . 10 gm. 



Technique: 



1. Fix the material in one of the above fixatives (I, II, III, IV 

 or V) and embed in paraffin wax. 



2. Fix sections to slides and remove paraffin wax with xylol. 



3. Rinse with two changes of absolute alcohol. 



4. Wash with 90% followed by 80% alcohol. 



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