516 SUMMARY OF CURRENT KKSKAKCHES RELATING TO 



(4) Staining and Injecting. 



New Staining Methods for Blood Smears.* — W. J. MacXeal and 

 P. A. Sclmle point out that the Romanowsky stain and its various 

 modifications possess the ability to differentiate chromatin by virtue of 

 the presence of both methylen-azure and methylen-violet. The combina- 

 tion of methylen-azure with eosin seems to decompose in alcohol, with 

 oxidation of the latter. 



The authors suggest the preparation of two permanent reagents, the 

 one containing eosin and the other methylen-blue and its derivatives. 

 Two stock solutions were prepared as follows : — 



Solution A — 



Eosin, w r ater soluble, yellowish . . 1 



Methylic alcohol, Merck's " Reagent " . 500 



Solution B — 



Methylen-blue, medicinally pure . . ' 1 



Methylen-azure . . . . .0*20 



Methylen-violet, commercial . . . 0'60 



Methylic alcohol, Merk's " Reagent" . 500*00 



" The dyes are thoroughly rubbed up in a perfectly clean mortar with 

 a few drops of the alcohol, so as to form a homogeneous paste. This 

 is then transferred to a bottle (capacity 500 c.cin.), and the mortar is 

 carefully washed clean with successive portions of methylic alcohol, 

 which are subsequently poured into the bottle. The remainder of the 

 500 c.cni. of methylic alcohol is added, the bottle thoroughly shaken, 

 stoppered loosely, and immersed in warm water (50° C.) for a time, and 

 again thoroughly shaken. It is well to keep it in a warm place for a 

 few days, shaking it at frequent intervals so as to separate the dyes 

 from the insoluble residue and bring them completely into solution. 

 Filtration is unnecessary. These solutions are kept in amber bottles 

 in a dark place, and remain in good condition for several months. 

 Small equal portions (30 c.cm.) are mixed together to form the staining 

 solution, which is then ready for immediate use and keeps well for a 

 few weeks. 



" The staining method is that described by Leishman, and already 

 too well known to require more than a hasty description. To a freshly- 

 made thin, dry blood-film one adds the staining solution, allows it to 

 stand one minute ; then dilutes with about an equal amount of distilled 

 water, and allows this resulting mixture to act for two to three minutes ; 

 then washes in distilled water until the desired differentiation is reached, 

 and dries the preparation between filter-papers. If the preparation is 

 to be mounted in balsam or cedar-oil, it should be very thoroughly dried, 

 best by standing for a day in the incubator, before mounting it." 



* Post Graduate, Nov. 1913, 6 pp. 



