CHAPTER XXXVI. . 545 



A measured volume of the distilled water is taken and to it are 

 added a few drops of hsematoxylin solution (5 per cent, in dist. H 2 0) 

 sufficient to tint it. Then a weak solution (1 per cent, in dist. water) 

 of potassium carbonate is added drop by drop until the colour of the 

 tinted water changes from yellow-red to reddish purple. In this 

 way the number of drops of the carbonate solution required to 

 neutralise a given volume of the distilled water is found. 



The slides are now placed in the stain, 1 drop Giemsa to 1 c.c. 

 neutralised distilled water for one hour. Transfer to a weaker 

 solution (1 drop stain plus 4 or 5 c.c. water) and leave overnight. 

 Remove excess of stain by washing in water. Differentiate stain 

 by carrying slides through different strengths of acetone mixed with 

 xylol, beginning with 95 per cent, acetone and ending with pure 

 xylol. Mount in dammar or Canada balsam. 



(If these instructions are carefully followed the results are excellent, 

 but care must be used.) 



1027. Giemsa Method for Staining Gut Flagellates (J. G. THOMSON). 



( 1 ) Fix wet sat. perchloride, 2 parts ; alcohol, 1 part. 



(2) Wash in weak alcohol (circa, 50 per cent.). 



(3) Wash in water (aq. dist.). 



(4) Wash in water, to which is added a few drops of Gram's iodin. 



(5) Wash in 1 per cent, solution of hypo. 



(6) Wash in running water. 



(7) Stain in Giemsa (1 drop, 1 c.c.) twelve hours. 



(8) Differentiate in (a) acetone, 95 per cent. ; xylol, 5 per cent., for 

 about five minutes ; then (ft) acetone, 70 per cent. ; xylol, 30 per cent. ; 

 (c) pure xylol to clear. 



(9) Mount in Canada balsam. 



1028. Iron Brazilin Stain (HICKSON). (1) Fix in Schaudinn's solution 

 for fifteen minutes. 



(2) Seventy per cent, alcohol for one hour. 



(3) Mordant for four hours in a 1 per cent, solution of iron alum in 

 70 per cent, alcohol. 



(4) Stain twelve to sixteen hours in a 1 per cent, solution of brazilin 

 in 70 per cent, alcohol. 



(5) Wash thoroughly in several changes of 70 per cent, alcohol. 



(6) Dehydrate and mount in balsam. 



1029. FONTANA'S Stain. (1) Fix in Hugo's fluid for one minute. 



Acetic acid (B.P.) . . . 1 c.c. 



Formalin . . . . . 20 ,, 



Distilled water . .100 



(2) Wash thoroughly in tap water. 



(3) Mordant. Slide should be gently warmed. 



Tannic acid .... 5 grms. 



Carbolic acid ..... 1 c.c. 



Distilled water . . . . .100 c.c. 

 M. 35 



