and Laboratory Methods. 1635 



[ NEWS AND NOTES. J 



A New and Rapid Method of Staining the Chromatin of the Malaria 

 Parasite ; A New Blood-stain. — Dr. L. B. Goldhorn, in the New York Uni- 

 versity Bulletin of the Medical Sciences (Vol. 1, No. 2), gives in detail a method 

 which he has worked out for staining blood with his well known polychrome 

 methylen blue mixture. He claims for the method that it shows, in addition 

 to all that may be seen with other stains, a cell-degeneration in infected blood 

 corpuscles which has not been seen heretofore. The method pursued is as follows : 



1. Yi^ fresh smears, after drying, in pure methyl alcohol or in " syn- 



thol " for fifteen seconds. 



2. Wash in running water, 



3. Stain in 0.1 — 0.2 per cent, aqueous solution of eosin for seven to 



thirty seconds. 



4. Wash in running water. 



5. Stain in solution of polychrome methylen blue for thirty seconds 



to two minutes. 



6. Wash thoroughly. 



7. Dry by rapid agitation in air ; not by use of filter paper or by heat. 

 Rapid fixation by short immersion in methyl alcohol was found as satisfac- 

 tory as the longer methods. 



No special brand of eosin is needed, and if desired erythrosin may be used 

 instead of eosin. 



The polychrome solution is prepared as follows : " Two grams of methylen 

 blue are dissolved in 300 c. c. of warm water and four grams of lithium carbonate 

 are added under constant shaking. Pour the mixture into an open porcelain 

 dish over a water bath, allowing the boiling water to touch the bottom of the 

 dish. Stir frequently with glass rod. Remove after fifteen to twenty minutes 

 and pour into a glass-stoppered bottle without filtering ; a bit of cotton may, 

 without disadvantage, be used in the funnel. Set aside for several days ; then 

 correct the reaction of the solution by cautious addition of four or five per cent, 

 acetic acid solution, until the dye is only very faintly alkaline. This point is 

 not very readily found ; it is probably best to acidify the dye first until blue 

 litmus paper shows faint pink above the blue portion where the stain has dyed 

 the paper, and then work backwards, until the stain gives the desired reaction. 

 Trial blood smears should be used to check the result. When the dye is of the 

 proper reaction it takes a good deal of eosin out of the red cells without giving 

 fhem a blackish appearance. A faintly acid dye gives fine chromatin staining, 

 but degenerative changes in the red blood corpuscles are not brought out. Simi- 

 lar results are obtained by staining too long in the eosin, or by staining in a 

 strong eosin solution." 



Certain difficult forms of malarial parasites give excellent preparations with 

 the polychrome stain. With ten seconds immersion, the nucleus of the " ring 



