TISSUE BASOPHILES 



244 



TISSUE CULTURE 



spreads of Loose Connective Tissue or 

 omentum. Their granules are readily 

 colored supra vitally with brilliant cresyl 

 blue, methylene blue and other stains. 

 Tissue basophiles disintegrate quickly. 

 Ivlaximow, A., Arch, f . mikr. Anat., 1913, 

 83 (1), 247^289 gives the following 

 metachromatic stain for mast cells. 

 Sections of abs. ale. fixed tissues are 

 stained 24-48 hrs. in sat. thionin in 50% 

 ale. Staining can be reduced to 20 min. 

 by adding 4 drops 3% NaoCOs to 20 cc. 

 thionin sol. and filtering before use. 

 IVIaximow gives technique for smears 

 and spreads fixed in formalin Zenker. 

 See his beautiful colored plates. See 

 Toluidine Blue Phloxinate. 



Holmgren and Wilander (H. and O., 

 Ztsciir. f. mikr. Anat. Forsch., 1937, 

 42, 242-278) recommend fixation in 10% 

 aq. basic lead acetate and staining with 

 1% ale. Toluidin blue. They show 

 that fixation in formalin-alcohol gives 

 very inferior results. In their opinion 

 the metachromatic substance colored is 

 identical with Heparin. 



Sylven, B., Acta Radiol., 1940, 21, 

 206-212 has followed this matter up by 

 subjecting rats and guinea pigs (in which 

 the basophilic granules are said to be 

 less soluble in water than in most other 

 animals) to Gamma rays. He fixed the 

 tissues in weaker aq. basic lead acetate 

 (4%) for 24 hrs., stained paraffin sec- 

 tions with J% aq. toluidin blue and 

 other dyes, and reached the conclusion 

 that the radiation brings about liberation 

 of organic sulphuric acids of high molec- 

 I ular weight. It would be natural to 



investigate the relation if any between 

 heparin and the basophilic granules in 

 buffy coat of centrifuged human blood 

 containing say 0.5% basophiles and in 

 that of certain turtles in which the per- 

 centage is as high as SO as well as in 

 livers. 



Another method of study is to investi- 

 gate heparin in relation to the charac- 

 teristic dissolution of basophiles 2 days 

 after the intraperitoneal injection of egg 

 albumen (Webb, R. U., Am. J. Anab., 

 1931-32,49,283-334). 

 Tissue Culture. — Written by Wilton R. 

 Earle, National Cancer Institute, Be- 

 thesda, Md. — By these methods a small 

 clump of cells can be removed from an 

 organism and maintained in a condition 

 of survival or growth for periods rang- 

 ing from a few hours for some cells to 

 an indefinite number of years for others. 

 While so maintained they can be ex- 

 amined microscopically at various mag- 

 nifications. The differentiation of em- 

 bryonic tissues can be followed (Fell, 

 H. B., J. Roy. Micr. Soc, 1940, 60, 95). 

 Malignant cells may be grown and 



studied for an extended interval and 

 their characteristics compared with 

 those of normal cells or with malignant 

 cells in vivo (Earle, W. R., J. Nat. 

 Cancer Inst., 1943, 4, 165). Cell form, 

 size, internal motion, locomotion and 

 rate and manner of cell proliferation can 

 be routinely studied either visually, or 

 by means of photographic records, in- 

 cluding time-lapse cinematography 

 (Earle, W. R., J. Nat. Cancer Inst., 

 1943, 4, 147). The tissue cultures can 

 be killed, fixed in situ and stained, or 

 even examined unstained by means of 

 the electron microscope (Porter, K. R., 

 Anat. Rec, 1946,94. 490). 



In addition nutritional and physio- 

 logical studies are possible. The cul- 

 ture medium can be modified by the 

 addition or omission of various nutri- 

 tional elements or other physiologically 

 active substances and the influence of 

 this altered medium on the cells grown 

 in it studied. Tissue cultures can also 

 be used for investigation of both pro- 

 toxoan and bacterial parasites of tissues 

 (Fischer, A., Gewebezuchtung. Munich: 

 R. Muller, 1930), and in the production 

 of vaccines. 



Culture Support. For the satisfac- 

 tory routine maintenance of cultures 

 of most tissue cells a solid support for 

 their growth and migration is required. 

 Various types of supports have been 

 employed, such as silk thread, spider 

 web, glass wool, lens tissue, cellophane, 

 gelatin, and agar, and for simple cul- 

 tures the glass surface of the culture 

 dish. By far the most satisfactory 

 support is provided by placing the cell 

 clump in a thin layer of fluid plasma, by 

 clotting the plasma into a solid gel and 

 by addition of a little tissue extract or 

 thrombin. When of correct consistency 

 the clot is a solid, somewhat elastic, 

 optically clear gel, of a fibrillar struc- 

 ture which enables the cells to migrate, 

 through it, although they exhibit a 

 tendency to collect at its surfaces. 

 With such a matrix, culture main- 

 tenance and growth are usually much 

 more satisfactory than with any other 

 type of solid support. (1) There is 

 better contact of the explant surface 

 with the threads of the fibrillar matrix. 

 (2) Adhesion of cells to a solid support 

 facilitates cleavage since the ceils 

 finally pull apart by adhering to the 

 solid medium and by migrating in op- 

 posite directions. (3) The freshly 

 prepared fibrin clot contains some 

 serum which enhances the growth of 

 many cell types. (4) The fibrin matrix 

 reduces loss of cells by their being 

 washed out of the culture in changing 

 the culture fluid. (5) It is also possible 



