ISOLATING BACTERIA FROM TISSUES I09 



sometimes necessary to fix pieces of the tissue in alcohol or 

 in some other fixing fluid for sectioning and staining, pre- 

 paratory to studying them.) 



Preserve one of the cover-glass preparations to accompany 

 the notes. 



160. Making cultures from animal tissues. Heat a platinum 

 spatula to a white heat in a gas flame and scorch the surface 

 of the organ. Flame a pair of fine forceps, tear an opening 

 through the scorched surface, and crush a bit of tissue under- 

 neath it. With the platinum loop take up a loopful of the 

 crushed tissue, with which inoculate the media. It is also 

 desirable to inoculate a tube of slant agar with the needle by 

 drawing it over the surface of the medium after charging it 

 with tissue. In making plate cultures use a loopful of the 

 crushed tissue for the first tube. The quantity of the tissue 

 necessary to give a desired number of colonies cannot be 

 anticipated, although experience in working with different 

 organisms in animals renders one able to approximate the 

 amount required. 



