STAINING, PRACTICAL AND THEORETICAL 



Navashin's Fluid 



Recommended for : 



Cytological study (usually of plant tissues). 



Recipe : 



Chromic acid . . . . . . . . 1-5 gm. 



Acetic acid 10% aqueous . . . . 100 ml. 



Distilled water . . . , 60 ml. 



Formalin (formaldehyde 40%) . . 40 ml. 



Note. — The formaldehyde should not be added until the solu- 

 tion is required for immediate use. 



Technique: 



Fix material for one to two days ; then wash twelve to sixteen 

 hours in running water. Dehydrate ; clear and embed. 



Orth's Fluid 



Recommended for : 



Demonstration of acute degenerative processes to be stained 

 with Giemsa, Wright, or Leishman Stain, and for Intestine. 



Recipe : 



Potassium dichromate . . . . 2-5 gm. 



Sodium sulphate crystals . . . . i gm. 



Distilled water . . . . . . 100 ml. 



Formalin (formaldehyde 40%) . . 10 ml. 



The last item should not be added until the fixative is required 

 for immediate use. 



Technique: 



Fix pieces of tissue up to i cm. in thickness for two to four days ; 

 then wash in running water from twelve to twenty-four hours. 

 Transfer to 80% alcohol ; dehydrate ; clear and embed. 



Remarks: 



This fixative may be employed as a general fixative for animal 

 tissues. It is useful where a firm consistency of tissue is required, 

 but it is not recommended for sharp histological detail. The value 



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