SECTION TWO 



I 



ORANGE G - CRYSTAL VIOLET (Bensley) 



For secretion antecedents of serous or zymogenic cells. 

 This stain is particularly suitable for sections of the stomach 



or pancreas 



Solutions required: 



A. Osmic acid 2% . . . . • • 4 ml. 

 Potassium dichromate 5% . . 4 ml. 

 Glacial acetic acid . . . . i drop 

 Distilled water . . . . 2 ml. 



B. Neutral gentian 



Orange G 8% aqueous . . • . 25 ml. 



Crystal violet 4% aqueous . . 25 ml. 



Mix thoroughly by shaking until almost complete 

 precipitation takes place ; then allow the preparation 

 to stand for an hour, afterwards collecting the preci- 

 pitate on a filter. Wash the precipitate on the filter 

 with about 250 ml. distilled water; then dry and dis- 

 solve it in 25 ml. absolute alcohol. 



C. Solution B (as above) . . . . 10 ml. 

 Alcohol 20% . . . . Sufficient to impart a 



rich port-wine colour. 



Allow to stand for twenty-four hours; then filter. 



D. Absolute alcohol . . . . i volume 

 Clove oil . . . . . . • • 3 volumes 



Technique : 



1. Tissues are fixed in Solution A (as above) for twenty-four 

 hours, and afterwards embedded in paraffin wax in the usual man- 

 ner. 



2. Stain sections for twenty-four hours in Solution C (as above) ; 

 then pour off excess stain, and blot the preparation carefully. 



3. Dehydrate by immersing in two or three changes of acetone. 



4. Clear in xylol; then differentiate in Solution D (as above), 

 controlling under the microscope. 



5. Rinse in two changes of xylol; then mount in balsam. 



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