UNIVERSITY OF CALIFORNIA PUBLICATIONS 



IN 



ZOOLOGY 



Vol. 16, No. 4, pp. 55-62, 2 figures in text November 20, 1915 



THE CULTIVATION OF TISSUES PROM 

 AMPHIBIANS 



BY j 



JOHN C. JOHNSON \ 



This paper gives the resTilts of studies and experiments made during 

 tlie last eight months on the cultivation of tissues in vitro, principally 

 from amphibians ; together with a .slight modification in technicpxe 

 adopted in order to get a greater percentage of more active and even 

 outgrowths from these ti.ssues. In general, the technique u.sed was that 

 as fir.st devised by Professor Ross G. Harrison in his successful culti- 

 vation of nerve tis.sue, modified and improved by Dr. Alexis Carrel 

 and Montrose T. Burrows of the Rockefeller Institute for Medical 

 Research. The usual thick .slides with deep cups were used, over 

 which were placed cover-slips closely sealed by vaseline. No. 1 cover- 

 slips proved to be the best, as with these the oil-immersion lens could 

 be used to greater advantage. 



Tissues were cultivated in plasma, lymph, blood serum, and blood 

 serum mixed with Griibler's gelatine of different proportions and 

 strengths. Lymph often gave good results, but the fluid drawn after 

 the first few minute.s generally became too thin to coagulate and thus 

 was of little value. Pure plasma behaved in just the reverse manner, 

 coagulating so readily as to be of great inconvenience. Best results 

 were obtained by a medium first devised by Professor S. J. Holmes, 

 consisting of blood serum and a two or three per cent Griibler's gela- 

 tine solution mixed about half and half. The reason for such a 

 mixture rather than pure blood or blood serum is that the fluid can be 

 kept, it seems, almost indefinitely. Serum two weeks old was just as 

 effective as newly prepared material. 



BO 



