CH. A'] STAINING AND PERMANENT MOUNTING 315 



Dehydrate in 95% and absolute alcohol, clear and mount in 

 acid balsam. Acid balsam injures hematoxylin, but is necessary 

 for the red in the picro-fuchsin. 



I/Ook out for mercuric chlorid crystals in the sections (§ 413, 

 477)- 



§ 468. Hematoxylin and Mucicarmin. — Tissues and organs 

 are best fixed in Zenker's or mercuric chlorid. Small intestine is 

 one of the most striking and instructive organs for this double stain . 

 Make the sections by the paraffin method, but do not fasten them 

 to the slide with collodion, for collodion stains with mucicarmin 



(§ 389). 



Stain 1 to 24 hours in mucicarmin. Wash off the stain with 

 water 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. 



WEIGERT'S ELASTIC STAIN, WITH PICRO-FUCHSIN 

 AND MUCICARMIN 



§ 469. Elastic Stain. — Take a slide of sections made either 

 by the paraffin or the collodion method (§ § 439, 451) from alcohol 

 and put the slide into a jar or a shell vial of the stain. This is an 

 alcoholic stain (§ 461) hence the sections should not be washed in 

 water. Allow the stain to act from y 2 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., counter- 

 stain with picro-fuchsin of % the strength given in the regular 

 stain (§ 424, 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 

 (§ 3 8 7)- The elastic tissue should be almost black ; white fibrous 



