STAINING, PRACTICAL AND THEORETICAL 



3. Transfer to elastin stain for at least two hours at 37° C. or 

 for one half to one hour in an oven at 60° C. 



4. Blot and treat with absolute alcohol for three to five minutes. 



5. Rinse with water and counterstain for three minutes with 

 neutral red (Jensen). 



6. Rinse and differentiate the neutral red for a few seconds in 

 absolute alcohol. 



7. Rinse in distilled water, then pour on 0-5% picric acid 

 aqueous and wash off immediately with running water. 



8. Blot; dehydrate in absolute alcohol; clear in xylol and 

 mount. 



Results: 



Elastic fibres: blue-black. Nuclei: red. Erythrocytes and 

 muscle: yellow. 



Notes: Best results are obtained after the stain has been kept in 

 stock for several weeks, when it becomes perfectly selective and 

 remains so indefinitely. 



The use of Coplin's jars, which can be " topped-up " occa- 

 sionally to make good loss by evaporation, is to be recommended. 



Picric acid gives a beautiful contrast to the neutral red and 

 enhances the appearance of the elastic fibres by causing them to 

 stand out against a neutral background. Care must be taken when 

 using it, however, as overstaining tends to give the red nuclei an 

 unpleasant brownish tinge. It is perhaps advisable, until the 

 technique has been mastered, to use neutral red only, ensuring 

 that it is properly differentiated in absolute alcohol. 



It is claimed that this modification gives greater selectivity than 

 either Sheridan or Weigert elastin stains, and consistently excellent 

 results are obtained provided the stain is properly prepared. 



Solutions of Moore's elastin stain will keep for several years 

 without deterioration. 



The dry stain requires time and great care for its preparation; 

 the majority of workers will, no doubt, wish to purchase the stain 

 ready for use, but for those who have the time and prefer to 

 prepare the stain themselves, the method is given above. 



References : 



Moore, G. W. (1943). 

 Gurr, E. (195°^. iQS^). 



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