54 PARASITIC AMCEB^ OF MAN. 



ful in demonstrating the relation that the amoebae 

 bear to the lesions which are present. Various stain- 

 ing methods are used for this purpose, the most useful 

 of which is probably Mallory's stain, which differen- 

 tiates the amoebae in tissues in a very satisfactory 

 manner. 



Mallory's Method. Small pieces of tissue are 

 hardened in various strengths of alcohol, as is usual, 

 and imbedded in paraffin. As thin sections as pos- 

 sible should be cut and stained for from 3 to 5 

 minutes in a saturated aqueous solution of thionin; 

 differentiated in a 2 per cent, aqueous solution of 

 oxalic acid for l / 2 to 1 minute; washed in water; 

 dehydrated in absolute alcohol; cleared in xylol and 

 mounted in xylol balsam. 



With this method the nuclei of the a<moebae stain a 

 brownish red, while the nuclei of other cells stain 

 blue. 



Safranin. A good stain for demonstrating the 

 amoebae in tissue is safranin. The tissues may be 

 hardened in alcohol or in Flemming's or Zenker's 

 fluids, and then imbedded in paraffin. The following 

 solution of safranin is used for staining: Equal parts 

 of a saturated aqueous solution of " safranin soluble 

 in water " and a saturated alcoholic solution of 

 " safranin soluble in alcohol." 



The sections are stained in this mixture for from 

 6 to 24 hours, washed in water, and differentiated in 



