SECTION TWO 



Technique: 



1. Material should be fixed in io% formalin and embedded 

 in paraffin wax. Sections are cut 6 to i2/i in thickness. 



2. Fix sections to slides; remove paraffin wax and take down 

 to 70% alcohol by the usual stages. 



3. Pass through 30% alcohol; then stain in Solution C for five 

 minutes. 



4. Rinse in two changes of tap water. 



5. Immerse in Solution D for one to two minutes. 



6. Wash in running water for two to five minutes to remove the 

 unchanged molybdate. 



7. Dehydrate; clear in xylol and mount. 



Note: A deep yellow filter is of great help in microscopic 

 examination, although not necessary. 



Results: 



Nuclei, dark blue; nucleoli of neurones, red; axial substances 

 of nerve fibres, dark to pale blue ; cuticular substance (including 

 myelotheca) of nerve fibres, red ; neurilemma (of Glees), purplish 

 red. 



Notes: 



(a) To eliminate all myelin, sections should be passed through 

 Cellosolve after the alcohols. The same precaution should be 

 observed when preparing tissue for embedding. 



(b) The essence of this technique is that the lead haematoxylin 

 reduces the ammonium molybdate to form a blue lake, which 

 makes it possible to employ only the minimum exposure to 

 haematoxylin, thereby leaving the erythrophile (" Fuchsino- 

 phile ") parts of the neurone red. 



(c) The Falg technique, introduced later (MacConaill & 

 Gurr, 1959, i96ort, see pages 198-203 of this book) is simpler to 

 perform and is considered to give more satisfactory results than 

 the above method. 



Reference: MacConaill, M. A. (1949, 1951). 



