Ch. XI] STAINING MICROSCOPIC OBJECTS 397 



and then stain with hematoxylin. Do not stain too deeply. Wash 

 with water, dehydrate, clear and mount in natural balsam. Nuclei 

 will be bluish or purple and the cells containing mucus will be rose red. 

 The goblet cells of the villi stand out like small red goblets, and if 

 any mucus is streaming out of them it will be red. 



§ 645. Elastic tissue stain. — Take a slide of sections made either 

 by the paraffin or the collodion method from alcohol and put the slide 

 into a jar or a shell vial of the stain. This is an alcoholic stain, hence 

 the sections should not be washed in water. Allow the stain to act 

 from a half hour to an hour. Wash off the superfluous stain with 

 95% alcohol from a pipette or by rinsing in a jar of 95% alcohol. 

 It is better in either case to use the pipette and clean alcohol for the 

 final washing. 



This stain alone gives a bluish tone to the entire tissue, the elastic 

 tissue being stained a very deep blue. For greater contrast and to 

 bring out the white fibrous tissue, muscle, etc., counterstain with 

 picro-fuchsin of one-fourth the strength given in the regular stain 

 (i.e., picro-fuchsin 1 part, distilled water 3 parts). 



Dip the slide of sections into distilled water, and then into a shell- 

 vial of the stain. Stain 15 to 30 seconds on the average. Wash in 

 distilled water and dehydrate in 95 % alcohol and absolute if necessary, 

 then clear in carbol-xylene and mount in acid balsam (§ 547). The 

 elastic tissue should be almost black; white fibrous tissue, red; muscle, 

 blood, and epithelia yellow or yellowish. Arteries are excellent for 

 this combination. 



§ 646. Combined elastic mucicarmine and picro-fuchsin stain. — 

 For this, one should take some object that is known to contain elastic 

 tissue, mucus, white fibrous tissue, and muscle. (The non-cartilag- 

 inous part of the trachea is excellent). The organ should have 

 been fixed in mercuric chlorid or Zenker's fluid (§ 579, 592), for this 

 preparation. The sections should be made by the paraffin method 

 and no collodion should be used for fastening the sections to the slide 

 (§ 622), for collodion is stained by mucicarmine. 



(1) Stain first in the elastic stain 1 hour. Wash well with 95% 

 alcohol and then with water. 



(2) Stain in a shellvial or jar of mucicarmine (§ 549) from 1 to 24 



