60 ANILIN COLOURS GIVING INDIRECT NUCLEAIt STAINS. 



The results depend in great measure on the previous treat- 

 ment of the tissues. If you have given them a prolonged 

 fixation in Flemming' s strong chromo-aceto-osmic mixture, and 

 have washed out after staining with acid alcohol and cleared 

 with clove oil, you will get, with some special exceptions, 

 nothing stained but nucleoli, and the chromatin of dividing 

 nuclei, that of resting nuclei remaining unstained. If you 

 have given a lighter fixation, with Flemming's weak mixture, 

 or some other fixing agent not specially inimical to staining, 

 and have washed out after staining with pure alcohol, you will 

 get the chromatin of resting nuclei stained as well. With some 

 of these stains Victoria, for instance it is easy to get cyto- 

 plasm stained, in a lighter tone than the nuclei, by merely 

 washing out lightly. 



100. Victoria Blue (Victoriablau) . (LUSTGAETEN, Med. Jahrb. 

 k. Ges. d.Aerzte zu Wien, 1886, p. 285 91). Stain (specimens 

 strongly fixed in " Flemming " some hours, lightly fixed speci- 

 mens a few minutes) in saturated aqueous solution. Wash 

 out in pure alcohol (about one minute, more or less). You 

 may clear with clove oil, but you had perhaps better take cedar 

 or bergamot oil, as clove oil washes out the colour very freely. 



A most brilliant and useful nuclear stain, and one that I 

 think should be particularly recommended to the beginner, as 

 it is particularly easy to work with. Chromatin and nucleoli, 

 blue. Cytoplasm, if well washed out, colourless ; if less washed 

 out, green or greenish blue. The " spongioplasm " is very 

 finely brought out by this method. 



Victoria has a special affinity for elastic fibres. For this 

 object, Lustgarten recommends an alcoholic solution of the 

 dye diluted with two to four parts of water. Fixation in 

 chrom-osmium, or at least in a chromic mixture, is, I believe, a 

 necessary condition to this reaction. And you must stain for 

 a long time. 



101. Anilin Green. Use precisely as directed for Victoria blue, supra. 

 An extremely delicate and absolutely precise nuclear stain, nucleoli being 

 peculiarly brilliantly stained by it. I am unfortunately unable to trace the 

 history of the colour used by me, which may be identical with the Solidgriin 

 of Flemming (Arch.f. mik. Anat., xix, 1881, pp. 317 and 742). It is well to 

 be even more careful in the use of clove oil than in the case of Victoria blue. 

 This colour seems not so generally useful as Victoria, as it does not give so 

 bold a stain. 



