CONNECTIVE TISSUES. 349 



Plasma Cells. 



700. Plasma Cells and " Mastzellen " ; Generalities. Plasma 

 cells, of which " Mastzellen ' are a sub-species, are cells 

 found in or along with connective tissue, and distinguished 

 by their hypertrophied and very granular cytoplasm and 

 poorly staining nucleus. The granules are highly basophi- 

 lous, much more so than the nuclei ; they stain with special 

 energy with basic aniliiis, and mostly nietachroniatically. 

 They do not, however, stain with pure methyl green. The 

 nuclei either do not stain at all or not in the normal way, 

 except with pure methyl green. 



According to UNNA in Encycl. in Hi. Techn.j 1910, ii, 

 p. 411, material should be fixed in chemically pure absolute 

 alcohol and sectioned in celloidin. Care should be taken to 

 avoid contamination of the liquids by tannin ; corks, and 

 supports for imbedding, should be soaked for some hours 

 before use in 2 per cent, carbonate of soda. 



701. MastzeUjm (NoRDMANiSFj Bcitr. z. Kenntniss d. Mastzellen, 

 Inaugural diss., Helmstedt, 1881). A concentrated solution of vesuvin 

 containing 4 to 5 per cent, of hydrochloric acid. Stain for a few minutes, 

 and dehydrate with absolute alcohol. 



702. Plasma Cells, UNNA'S Later Methods (UNNA, in E-ncyd. 

 mik. Teclm., 1910, ii, p. 411). 



A. For Large Plasma Cells. 



(1) Ten minutes in Griibler's polychrome methylen blue 

 solution, wash and drain. Fifteen minutes in 1 per cent, 

 orcein solution (Griibler), without acid ; absolute alcohol, so 

 long as methylen blue conies away abundantly ; bergamot 

 oil, balsam. 



(2) Methylen blue as above, 2 minutes. Wash well. 

 Then two minutes in glycerin-ether mixture* (Griibler) 

 diluted with 4 volumes of water. Wash thoroughly (2 to 5 

 minutes) ; absolute alcohol, bergamot oil, balsam. 



(3) Modification of a method of PAPPENHEIM (Virchow's 



* Glycerin ether C G H JO O 3 , is a glycerin anhydride. It is a differen- 

 tiating agent for basic dyes. The glycerin-ether mixture in question 

 contains alcohol and glycerin, and can be obtained from Griibler. 



