218 HISTOLOGICAL PREPARATIONS 



For triple staining a selective dye is chosen which will stain the various 

 tissues different colours. This method of staining enables the lesions produced 

 by the organisms to be studied. The stains ordinarily used are Orth's picro- 

 carmine or haematoxylin in conjunction with aurantia or eosin. The following 

 are the formulae most commonly in use : 



STAINING SOLUTIONS. 



Dilute aqueous solution of eosin. 



Water-soluble eosin, - 0'50 gram. 



Distilled water, - - 300 c.c. 



Filter. 



Solutions of fluorescein, aurantia, vesuvin (0'5 per cent.), etc., are prepared in a similar 

 manner. 



Bcehmer's hcematoxylin. 



Make up the two following solutions : 



(a) Hsematoxylin crystals, - - 1 gram. 



Absolute alcohol, - - - 10 c.c. 



Pour the solution into a well-stoppered bottle. 

 (6) Potash alum, ----- - 20 grams. 



Distilled water, ... - 200 c.c. 



Dissolve in the warm and filter when cool. 



Allow to stand for 24 hours and then mix the two solutions a and b ; leave 

 the mixture exposed to the air for a week, then store in a well-stoppered 

 bottle and filter immediately before use. 



Hcematein. 



Prepare the two following solutions : 

 (a) Hsematein, - 1 gram. 



Absolute alcohol, - - 50 c.c. 



(6) Potash alum, - - - 50 grams. 



Distilled water, - - 1000 c.c. 



The potash alum is dissolved in the warm and added immediately to the 

 haematein solution. Let the mixture cool in the air and then filter. 



Orth's carmine. 



Saturated aqueous solution of carbonate of lithia, - - 100 c.c. 

 Carmine No. 40, - - 2*50 grams. 



Dissolve by trituration in a mortar in the cold. 



Orth's alcohol carmine. 



Orth's carmine, - 5 volumes. 



95 per cent, alcohol, ....... 1 volume. 



Mix. 



The latter solution only should be used for staining sections fixed with 

 Mayer's albumin, as the former the non-alcoholic solution dissolves 

 albumin. 



Orth's picrocarmine. 

 Mix. 



Orth's carmine, - 1 volume. 



Saturated aqueous solution of picric acid, - 1-2 volumes. 



After staining in the picrocarmine solution, the sections should be trans- 

 ferred to the following fixing solution : 



Absolute alcohol, - - 70 c.c. 



Saturated aqueous solution of picric acid, - - - - 30 ,, 

 Pure hydrochloric acid, - - 0'50 gram. 



