20 



EXERCISE V. 



INOCULATING TUBES OF BOUILLON, AGAR AND GELATIN. 



17. General directions. Inoculate a tube of bouillon, 

 two (one inclined the other not) of agar and one of gelatin 

 from a culture of Bacillus coli communis which will be 

 furnished. 



Wipe out the slides and transfer the cover-glasses to the 

 alcohol ( 2 e). 



Read the chapters in the text-books on inoculating media 

 or making tube cultures. 



18. Inoculating bouillon. In making this culture care- 

 fully remove the plug from the tube of bouillon by first 

 twisting it around to detach any adhesions and then pull it 

 straight out. Pass the open end of the tube quickly 

 through the gas flame. The plug, which has meantime 

 been carefully held, is partially replaced and the tube re- 

 turned to its stand. Treat the tube containing the culture 

 (which has been furnished) in the same manner. Then 

 place the two tubes side by side between the thumb and fore 

 finger of the left hand and grasp them about the middle of 

 the upper half. Sterilize the platinum loop by passing it 

 through the gas flame, care being taken that the handle is 

 flamed for a distance of at least 15 cm. Then carefully 

 remove the plugs from the tubes and hold them between the 

 fingers in such a manner that the tube ends will not touch 

 anything during the inoculation process. Insert the wire 

 loop carefully into the culture and transfer a loopful of the 

 culture to the tube of bouillon and gently rinse it from the 

 loop. The loop is then withdrawn, the plugs replaced in 

 their respective tubes and the loop flamed and put aside. 

 Label the freshly inoculated tube with the name of the 

 organism, source and date. Stand it in a tray or cup and 

 place it in the incubator. This should be kept at a temper- 



