SECTION SEVEN 



2. Drain and leave to dry, then use as follows (within a few hours 

 at latest in the case of solution D) as the dried dye combination 

 does not keep well. 



3. Place a drop of blood on each slide. 



4. Cover with scrupulously clean coverslip and allow the blood 

 to spread. 



5. Seal the edges of the coverslips with soft paraffin wax (M.P. 

 38° C), and examine under the microscope. 



Results: 



With Solution C (Pinacyanol only) 

 Mitochondria in still living and motile cells are stained deep 

 blue to violet. 



With Solution D 

 Mitochondria stained as above; nuclei and other cell granules 

 are stained red. 



Reference: Hetherington, D. C. (1936), Stain Tech., 211, 153-4. 



PONDER'S STAIN (Kinyoun's modification) 



For differentiation of metachromatic granules of diph- 

 theria organisms 



Technique: 



1. Air-dried films are fixed by flaming; then stained for two 

 to seven minutes in the above solution. 



2. Wash in tap water ; then blot dry and examine. 



393 



