Staining Protozoa 



163 



The stain most useful is that of Romanowsky. It has many 

 modifications, of which the most used and best known are Giemsa's, 

 Jenner's, Leishman's, Wright's, and Marino's. These stains can 

 be bought either in solution or in tablet form ready for solution. 



Those most highly to be recommended are Wright's and Marino's. 



Fig. 3S. — Method of making dry film with two cover-glasses (from Daniels' 

 "Laboratory Studies in Tropical Medicine"). 



Wright's Blood-stain. — This is a modification of Leishmann's stain, to which 

 it is to be preferred because it can be made in a few hours instead of eleven 

 days. It combines the methylene-blue-eosin combination of Roman- 

 owsky with the methyl-alcohol fixation of Jenner. 



It is prepared as follows:* 



"To a 0.5 per cent, aqueous solution of sodium bicarbonate add methylene- 

 blue (B. X. or "medicinally pure") in the proportion of i gm. of the dye 



Fig. 36. — Method of making dry films with two slides (from Daniels' "Labora- 

 tory Studies in Tropical Medicine"). 



to 100 cc. of the solution. Heat the mixture in a steam sterilizer at 

 ioo°C. for one full hour, counting the time after the sterilizer has become 

 thoroughly heated. The mixture is to be contained in a flask of such size 

 and shape that it forms a layer not more than 6 cm. deep. After heating, 

 the mixture is allowed to cool, placing the flask in cold water if desired, and 



* Mallory and Wright, "Pathological Technique," 1911, p. 364. 



