SECTION TWO 



of the chromium chloride acetic acid (sokition A, above) did not 

 produce a positive stain with his method. 



(e) In the authors' experience a negative result was obtained 

 on tissue which had previously stained strongly if the paraldehyde 

 used in preparing solution B had not been obtained from a freshly 

 or recently opened bottle. 



(/) It is also stated that a staining time of over six hours is 

 not critical and although the normal islets in some tissues are stained 

 adequately in five minutes, a period of six hours was found to be 

 the optimum time for the evaluation of tumours. 



(g) Readers are referred to the original paper for more detailed 

 information. 



Reference: Sieracki, J. C, Michael, J. E. & Clark, D. A. (i960). 



PASINPS STAIN (Improved) 

 For differentiation of connective tissue 



Solutions required: 



A. Iron alum 2-5% aqueous. 



B. PasinVs stain: 



Unna's aniline blue-orcein . . 10 ml. 



Eosin bluish 2% in 50% alcohol. . 12 ml. 



Acid fuchsin . . . . . . 0-3 gm. 



Neutral glycerine . . . . • • 5 nil- 



Technique: 



1. Tissues should be fixed in Heidenhain's susa mixture and 

 embedded in L.V.N. Sections are cut 3/t in thickness. 



After removal of mercuric precipitate in the usual manner sec- 

 tions are mordanted in Solution A for twenty-four hours. 



2. Transfer to Solution B for three to ten minutes. 



3. Transfer to 95% alcohol and agitate for about one minute or 

 until the colour ceases to come out in clouds. 



4. Immerse in absolute alcohol for one minute ; then blot, clear 

 and mount. 



347 



