MEDICAL AND BIOLOGICAL STAINING TECHNIQUES 



8. Rinse with 70% alcohol. 



9. Rinse quickly with 90% alcohol. 



10. Dehydrate quickly but thoroughly with two changes of 

 absolute alcohol. 



11. Clear in xylol and mount in Canada balsam in xylol or in 

 Emexel. 



Results: 



Chromatin granules and nucleoli in early stages of micro- 

 sporogenesis are stained green while the linin threads are red. 

 Chromosomes are stained brilliant green in later stages. 



Reference: Cooper, D. C. (1931) American J. Bot., i8, 337. 



METHYL GREEN - ACID FUCHSIN 

 For chromosomes, etc., in plant tissue 



Solutions required: 



A. Methyl green 2% aqueous . . 100 ml. 

 Acetic acid 1% . . . . . . 2 ml. 



B. Acid fuchsin 1% aqueous. 



Technique: 



1. Sections are brought down to water; then stained from six 

 to seven hours in the methyl green solution. 



2. Wash in water until the stain is almost entirely removed from 

 the non-lignified elements (this process should be controlled by 

 examination under the microscope v/hile the preparation is still 

 wet). 



3. Rinse in water. 



4. Stain from five to ten minutes in the acid fuchsin solution, 

 controlling under the microscope to ensure that the green is not 

 extracted from the lignified tissues. 



5. Wash rapidly in 95% alcohol, followed by absolute alcohol. 



6. Clear in clove oil ; then pass through xylol and mount. 



Results: 



Cytoplasm and plastin, light red; chromosomes and nuclei, 

 green. 



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