FREEHAND SECTIONS 93 



For convenient reference, the process may be summarized, but it 

 must be remembered that all the schedules are intended merely to 

 introduce the beginner to the method. 



1. Sections in 95 per cent alcohol. 



2. Stain in safranin, 24 hours. 



3. Fifty per cent alcohol until the stain becomes weak in cellulose walls, but 

 not until it is removed entirely. 



4. Anilin blue, 2-10 minutes. 



5. Ninety-five per cent alcohol, 2-5 seconds. 



6. Ninety-five per cent alcohol, slightly acidulated with hydrochloric acid, 

 5 seconds. 



7. Ninety-five per cent alcohol, with or without a trace of sodium carbonate, 

 1 or 2 minutes. 



8. Absolute alcohol, 1-5 minutes. 



9. Xylol, 5 minutes. The xylol may be preceded by clove oil. 

 10. Mount in balsam. 



Lignified and suberized walls should stain bright red, and cellulose 

 walls, bright blue. To make this beautiful combination a success, it is 

 necessary to be very careful. If too much safranin is extracted at 

 stage 3, the acid at stage 6 will still further weaken the red stain and 

 the contrast will not be sharp. 



Safranin and light green (Land's schedule). — This is another beauti- 

 ful combination, and the student should be successful from the first, 

 since the light green is simpler to apply than either Delafield's haema- 

 toxylin or anilin blue. 



Land uses either aqueous, anilin, or alcoholic safranin, and uses the 

 light green in clove oil, or in a mixture of clove oil and absolute alcohol. 

 Make a saturated solution of light green in clove oil. Since the solu- 

 tion takes place slowly, the mixture should stand several days before 

 using. If a small quantity of absolute alcohol be added to the clove oil, 

 the stain dissolves more readily. For some structures the stain is more 

 brilliant than with the simple clove-oil solution. 



Sections from fresh material are fixed in 95 per cent alcohol; sections 

 from preserved material are rinsed in alcohol or water before staining. 

 The following schedule will summarize the method: 



1. Safranin, 2-24 hours. 



2. Fifty per cent alcohol, until differentiated. 



3. Dehydrate in 95 and 100 per cent alcohol. 



4. Light green (in clove oil), 3-30 minutes. 



