50 W. H. E M I G 



686. Iodine Green is a basic dye, light 4. Different plant tis- 

 sues are stained blue-green or dull blue without a trace of green. 

 Similar to Methyl Green, it should be replaced by the better dye, 

 Methylene Green, C. I. No. 924. 



689. Opal Blue, Aniline Blue alcohol soluble, Bleu Lumiere, 

 Gentiana Blue 6B, Spirit Blue is a basic dye, light 3 ; ^ gram in 95 

 ml. of 50 per cent alcohol, 5 ml. of 5 per cent ammonium alum, and 

 ^ ml. of acetic acid. The cytoplasm is more readily stained an 

 intense blue than are the nuclei. Opal Blue may be used whenever 

 the color produced by New Methylene Blue is too dark. In con- 

 trast staining use Biebrich Scarlet, C. I. No. 280, Crocein Scarlet 

 MOO, C. I. No. 252, or Orange II, C. I. No. 151, for 24 hours and 

 Opal Blue five minutes ; transfer the section from the stain directly 

 to 95 per cent alcohol for dehydration. 



692. Acid Fuchsine, Acid Azo Fuchsine, Acid Magenta, Acid 

 Rubine, Fuchsine S, Rubine S is an acid dye, light 2 to 3 ; i gram 

 in 100 ml. of distilled water and 1 ml. of 1 per cent sulfuric acid. 

 The dye sold previous to 1920 was a fugitive red dye, probably 

 Azorubine ; that now on the market, domestic or imported, if true 

 to name, gives a fuchsia to reddish violet of good fastness. By the 

 sulfonation of different Basic Fuchsines, various quantities of the 

 derived acid dye are red to violet depending on the particular basic 

 dye used in its manufacture. If a bright red is not obtained with 

 Acid Fuchsine, use Biebrich Scarlet, C. I. No. 280, on plant tissues 

 or Crocein Scarlet MOO, C. I. No. 252, on animal tissues. 



In the staining of animal tissues, Acid Fuchsine usually blends 

 with blue or violet dyes to give colors of little contrast. If Acid 

 Fuchsine is diluted with either Sun Yellow, C. I. No. 620, or Orange 

 II, C. I. No. 151, the contrast with blue stains will be brilliant. A 

 good combination of stains for whole mounts, invertebrates, chick 

 embryos, or paraffin sections of tissues includes a mixture of ten 

 parts Sun Yellow and one part Acid Fuchsine for five minutes and 

 a counterstain either in Aniline Blue, C. I. No. 707, 15 seconds, or 

 in Niagara Sky Blue, C. I. No. 520, 30 seconds. Another good 

 technique includes a mixture of ten parts Orange II and one part 

 Acid Fuchsine for one or two minutes and a counterstain in Aniline 

 Blue or Niagara Sky Blue. 



