1494 Journal of Applied Microscopy 



Calcification takes a dirty, cold blue, which can be readily distinguished from 

 colloid. 



Cartilage takes a reddish violet, which is very characteristic. 



Corpora amylacea also stain a reddish violet. 



The most valuable reactions with this stain are those with mucin, amyloid, 

 mast-cells, and the so-called cancer parasite. In staining for these the sections 

 should be dehydrated in alcohol and cleared in turpentine. The excess of 

 turpentine must be thoroughly blotted off before mounting in balsam, else the 

 stain will run and the specimens become blotchy. 



The reaction with amyloid as brought out by the method given above is very 

 striking and characteristic, and is particularly valuable in teaching work. The 

 amyloid stains a ruby red, which is sharply contrasted with the clear blue nuclei 

 and faint blue protoplasm of the living tissues. No other method brings out so 

 well the presence and location of small quantities of amyloid. The stain appears 

 also to give a permanent reaction ; in the ten months in which this stain has been 

 used in this laboratory no fading of properly prepared specimens has been 

 observed, and trial specimens exposed daily to sunlight have retained their color 

 for months. The apparent permanency and clearness of this reaction, as well as 

 the fact that the sections so treated can be preserved in balsam, gives this stain 

 a high place over the anilin dyes usually employed for amyloid reactions. 



Mucin stains a bright rose pink, which is very characteristic and brings out 

 the presence of mucin when the amounts are too small to be demonstrated by 

 other methods. It also distinguishes mucin from pseudomucin, the latter either 

 not staining at all or taking a very light blue tint. 



The method is also a most excellent one for the staining of mast-cells. The 

 best results are obtained by staining only ten seconds, washing thoroughly and 

 differentiating in alcohol. The nucleus stains a light violet, the granules a 

 fuchsin red. 



The so-called cancer parasite stains a rose pink, and may be seen as a point 

 in the protoplasm of the cell or as a slightly larger mass surrounded by a clear 

 zone containing radiating lines. A more advanced stage is seen as a reticular 

 mass replacing more or less of the cell protoplasm, and, in some instances, con- 

 tinuous with the mucin surrounding the cell nests. The resemblance to the 

 reaction with mucin may be noticed in passing. 



The specific reaction with the Gonococcus has already been mentioned. This 

 stain has, however, the further advantage in that the material may be stained in 

 the hanging drop and the life of the cell not destroyed, so that the movements of 

 the leucocyte containing the micro-organisms may be studied. 



From these investigations it seems that for ease of manipulation, wide appli- 

 cation and specific staining reactions Kresylechtviolett holds a very high place 

 among differential stains for diagnostic purposes, and that it is a most valuable 

 addition to the resources of the teaching laboratory. 

 Pathological Laboratory, University of Michigan. Ralph L. MorsE. 



