22 



taking care to use the particular brand of stains 



specified. 



Solution A. Methylene blue (pure)* ro part 

 Sodium carbonate* - 0*5 

 Ordinary water - 100*0 parts 



Keep in the sun, or by the kitchen fire or in a hot 

 incubator for two or three days until the solution has 

 a distinct purple tinge. The solution is useless until 

 this has developed. The solution improves with age 

 and exposure to sunlight. 



Solution B. Eosinf I part 



Water - 1000 parts 



This solution should be kept in a cupboard as it 

 becomes gradually decolorised by sunlight. 



For use take 5 c.c. of each stock solution and make 

 each up to 100 c.c. with ordinary water. 



To Stain.l Mix one part of blue and two of the 

 eosin solution and pour on the slides. Stain ten 

 minutes. Wash in a full stream of water. Blot and 

 dry but do not heat. The platelets and nuclei should 

 be a deep ruby red without any trace of blue. 



Note I. As it is the precipitate which results from 

 the action of the ' azure/ etc., on the eosin, which is the 

 active staining principle, this mixture must be used 

 fresh, at least a few minutes only after making. 



Note II. While ten minutes or less is quite 

 sufficiently long for staining with a good brand of stain, 

 yet for certain purposes it may be necessary to stain for 

 one or more hours. 



May be got in soloid form from Burroughs & Wellcome. 



t The eosin is water-soluble, of a yellow shade, or in other words pure eosin for 

 blood work, e.g., the brand known as B.A. It may be got in tabloid form. 



| Mix the solutions in the proportion of i : I, I : 1*5, i : 2, etc., and ascertain 

 which is the best proportion for each particular brand of stain, e.g., by staining a 

 trypanosome, malaria parasite, etc. 



