METHOD XIII. 



STROEBE'S METHOD. 



A method devised for the study of the processes of both 

 degeneration and regeneration of meduUated nerve-fibers in the 

 peripheral nervous system. May also be applied for the pro- 

 cesses of degeneration in the central system. A good general 

 method for sections of the spinal cord. 



REAGENTS REQUIRED. 



A. Fixing fluid, Miiller's fluid. — For formula see XI, A, p. 69. 

 For ordinary purposes make up about 500 cc. 



B. The stain. — 



Aniline blue (Griibler) i g. 

 Distilled water, 100 cc. 

 The freshly made solution is more trustworthy. 



C. Counterstain. — 



Safranin (soluble in water), i g. 

 Distilled water, 100 cc. 

 Dilute with an equal volume of distilled water at the time of using. 



D. Differentiating fluid. — 



Absolute alcohol, 100 cc. 

 Caustic potash (pure), i g. 

 Let stand 24 hours and then filter. To use, add about 40 drops (2 cc.) 

 to 30 or 40 cc. of pure 95 per cent, alcohol. 



PROCEDURE. 



I. To fix. — Anywhere from 8 to 40 days (depending upon the 

 animal) after the lesion or operation, remove the portion of the 

 nervous system which includes the point of injury and place it 

 in 20-30 volumes of Miiller's fluid (A) and set aside for 8-12 

 weeks. If kept in a thermostat at 38° C, the time may be 

 reduced to 4-6 weeks. In either case the fluid should be 

 changed after the first and third days, and several times during 

 the rest of the period of fixation. 



79 

 Digitized by Microsoft® 



