SECTION TWO 



WEIGERT - PAL TECHNIQUE 



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

 pheral nerves and ganglia 



Solutions required: 



Technique: 



1. Slices of the material 2 to 5 mm. thick are fixed in 10% 

 formalin ; then transferred to Solution A for four to seven days. 



2. Wash in running water for several hours; then dehydrate 

 and embed in Celloidin, L.V.N, or in paraffin wax, or cut frozen 

 sections (in which case 2% ammon. bromide should be added to 

 the formalin fixing solution). 



3. Sections 10 to 20^ in thickness are stained twenty-four to 

 forty-eight hours in a freshly prepared mixture consisting of i vol- 

 ume Solution B and 9 volumes Solution C. 



4. Immerse for one half to three minutes in Solution D ; then 

 rinse in distilled water. 



5. Differentiate in Solution E for one half to three minutes or 

 until the white matter is blue-black, and the grey matter almost 

 colourless. 



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