198 METHYLEN BLUE 



The effect is practically identical (except as regards the colour) 

 with that of a negative impregnation ivith silver tiitrate. 



S. Mayer {Zeit. zciss. Mik., vi, 1889, p. 422) stains tissues for 

 about ten minutes in a 1 : 300 or 400 solution of inethylen blue 

 in 0*5 per cent, salt solution, rinses in salt solution, and puts up 

 in the glycerin-picrate of ammonia mixture given § 382. The 

 images are generally positive after injection of the colour into 

 the vascular system ; negative after immersion of the tissues. 



TiMOFEJEW (Anat. Anz., xxxv, 1909, p. 296) impregnates for 

 fifteen to twenty minutes in a solution of 1 : 300 or 400 strength, 

 fixes with a very weak solution of ammonium picrate in salt 

 solution, and puts up in a mixture of 50 c.c. glycerin, 50 c.c. 

 water, and 35 c.c. saturated solution of the picrate : or fixes with 

 ammonium molybdate of 8 per cent, and mounts in balsam. 



385. Toluidin Blue or Thionin as succedanea of methylen blue. 

 Harris {Philadelphia Med. Journ., May 14th, 1898) has found 

 that there is no reaction of methylen blue that cannot be equally 

 well obtained with toluidin blue or thionin. For staining pieces 

 of tissue he takes : 



Toluidin blue, 0-1 per cent. sol. in physio- 

 logical salt solution . . . .2 parts. 

 Ammonium chloride 0-25 per cent, in water . 1 part. 

 Egg albumen . . . . . . 1 ,, 



For injections he uses 1 part of the dye to 1000 of physiological 

 salt solution. 



Any of the methylen blue fixing methods may be employed 

 and the whole technique is the same. 



L. Martinotti (Zeit. wiss. Mik., xxvii, 1910, p. 24) recom- 

 mends a polychrome toluidin blue, made by adding 0-5 per cent, 

 of lithium carbonate to a 1 per cent, solution of the dye and 

 keeping till a purple-red tone appears. Or, a stock solution made 

 of 1 grm. toluidin blue, 0-5 grm. lithium carbonate, glycerin 20 

 c.c, alcohol 5 c.c, and water 75 c.c. 



386. Goodpasture's Carbol-Fuchsin and Methylen Blue (Am. 

 Jour. Path., i, 1925, 550). This method is very useful for the 

 coloration of Negri bodies, bacteria, Rickettsiae, and a wide 

 variety of cytoplasmic inclusions. Sections from Zenker-fixed 

 material are stained for ten minutes in : 



Alcohol 20 per cent. .... 1000 c.c. 



Phenol (pure) . . . . . 1*0 ,, 



Anilin oil . . . . . . I'O ,, 



Basic fuchsin ..... 0-5 grm. 



" The finely powdered or granular dye dissolves easily and the 

 solution is immediately ready for use. Exposure to light and air 

 causes a precipitation of the dye in about two months, so that the 

 solution becomes weaker and must be discarded. It is convenient 



