MEDICAL AND BIOLOGICAL STAINING TECHNIQUES 



1 . Fix small pieces of tissue in absolute alcohol, with a mech- 

 anical agitator, for twelve to twenty-four hours, changing the 

 alcohol at intervals of one hour during the day. 



2. Clear in freshly filtered xylol. 



3. Infiltrate with and embed in wax, which must not be 

 plunged into water to hasten cooling. 



4. Clean slides, in readiness to take the sections, by washing 

 them several times in distilled water, then partially drying them 

 with absolute alcohol, and finally drying them with a dust-free 

 cloth. Store the slides away from dust and mineral matter until 

 they are required for use. 



5. Cut serial sections 3 to ^fi in thickness, taking particular care 

 at this stage that they are not contaminated with dust or mineral 

 matter. 



6. Press serial sections onto slides, without any fixative or 

 spreading agent, with the fingers which have been washed and 

 dried with absolute alcohol. 



Note: It is now, at this stage, more than ever necessary to guard 

 against contamination by dust. 



7. Mount alternate serial sections on albuminized slides for 

 normal histological staining and comparison later with the 

 incinerated specimen. 



8. The slides bearing the sections for incineration are placed in 

 a quartz-tube electric furnace, but if that is not available a muffle 

 furnace, the inside of which is entirely free from dust and debris, 

 will serve the purpose. 



9. Gradually raise the temperature so that it reaches a maximum 

 of 60° C. at the end of the first three minutes. 



10. During the next three minutes, gradually raise the tempera- 

 ture to 70° C. 



1 1 . Raise to 80° C. during the next two minutes. 



12. Raise to 200° C. during the next five minutes. 



13. During the next twenty-five minutes raise the temperature 

 at the rate of 90° C. per five minutes, when the maximum of 650 ° 

 C. will be attained. 



332 



