SECTION TWO 



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. 



The 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. 



WEIGERT - PAL TECHNIQUE 



For myelin sheaths in brain and spinal cord and for peri- 

 pheral nerves and ganglia 



223 



