STAINING, PRACTICAL AND THEORETICAL 



Schaudinn's Fluid 



Recommended for : 



Animal tissues in general. Protozoa. 



Recipe: 



Mercuric chloride saturated aqueous 66 ml. 

 Absolute alcohol . . . . • • 33 i^ih 

 Glacial acetic acid . . . . . , i ml. 



N.B. — The acid should be added immediately before use. 



Technique: 



Fix tissues for six to sixteen hours. Wash in several changes of 

 70% alcohol. 



Remarks: 



The fixative may be used at about 65° C. v^hen less time is 

 required for its penetration. 



Susa Fluid (Heidenhain) 



Recommended for : 



Animal tissues in general. 



Recipe: 



Mercuric chloride, saturated aqueous 50 ml. 



Trichloracetic acid . . . . . . 2 gm. 



Formalin (formaldehyde 40%) . . 20 ml. 



Distilled water . . . . • • 30 ml. 



Glacial acetic acid . . . . • • 4 nil. 



Technique: 

 Fix for five to twelve hours; then wash out with 95% alcohol. 



Remarks: 



Compatible with most stains, but not with Weigert's elastin 

 stain. Susa offers the advantage over most other fixatives in that 

 it causes less shrinkage and less hardening, thereby rendering 

 tissues easier to cut. 



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