Production of Sections 283 



will ruin them. From distilled water transfer to the 

 following : 



Stock solution hsematoxylin, as above ... 5 c.c. 

 Distilled water or alum-water 95 c.c. 



Instead of the plain distilled water it is better to dilute the 

 stock solution with weak alum-water, of which a stock 

 solution may be made up as follows : 



Alum ... ... ... ... 10 grammes. 



Distilled water 1,000 c.c. 



The strength of the solution must be varied to suit the 

 work. An endeavour should be made to so gauge the 

 strength that the solution will take several hours to 

 thoroughly stain the nuclei without affecting the cytoplasm 

 too deeply. 



When stained, transfer to tap-water five minutes, then 

 place in distilled water a few minutes. If accidentally 

 stained too deeply, alum water is the remedy. If the 

 process cannot be completed at this stage, the hsematoxylin- 

 stained sections may be kept in 50 per cent, alcohol for 

 a time ; water will bleach them in a few hours. Prom 

 distilled water pass the sections into Bismark brown — full 

 strength as given in the formula — for about ten minutes. 

 Thence pass gradually through the various grades of 

 alcohol to 90 per cent., say, ten minutes in the 30 per cent, 

 and 5 minutes in the subsequent grades. 



From 90 per cent, alcohol clear the sections in xylol- 

 phenol by placing the slide, section downwards, in a 3-inch 

 by 1-inch trough containing a little of the clearing agent. 

 Having first wiped off the superfluous alcohol, the slide 

 should be supported at one end by a strip of wood, other- 

 wise the sections may be damaged by contact with the 

 bottom of the trough. 



Xylol-phbnol Formula. 



Pure xylol ... ... ... 100 c.c. 



Absolute phenol 100 grammes. 



Dissolve with gentle heat, and filter. 



