SECTION FOUR 



6. Wash well with water. 



7. Stain with solution C for ten minutes. 



8. Wash with water; drain and remove excess water, but do 

 not allow the preparation to dry. 



9. Place the slide under the microscope; then cover the pre- 

 paration with orange tannin, by means of a pipette. 



10. Observe the progress of the staining under the microscope 

 until the orange tannin has replaced the blue in the cytoplasm. 



1 1 . Withdraw excess fluid from the slide by means of a piece 

 of filter paper to avoid the risk of spilling over the microscope stage 

 and condenser. 



12. Take the slide away from the microscope and wash well 

 with 95% alcohol. 



13. Dehydrate in absolute alcohol. 



14. Clear and complete differentiation in aniline oil. 



15. Rinse with cedarwood oil. 



16. Drain and remove excess cedarwood oil from around the 

 preparation by blotting or wiping with a clean fluffless duster. 



17. Mount in Cristalite or Canada balsam in Xylol or Emexel 

 mountant. 



Results: 



Chromosome threads, blue. Metaphase chromosomes, red. 

 Cytoplasm, pale yellow. 



Reference: Bolles-Lee, nth edition, p. 664. 



COPPER CHROME HAEMATOXYLIN (Bensley) 



For mitochondria 



Solutions required: 



A. Altmann's Fluid 



B. Copper acetate, saturated aqueous 



C. Haematoxylin 10% in absolute alcohol 

 ripened . . . . . . • . 5 ml. 



Distilled water . . . . . . 90 ml. 



297 



