CULTURE MEDIA 



95 



sterilized in the autoclave. This medium is used for cultivation 

 of molds. 



MEDIA CONTAINING UNCOOKED PROTEIN. 



Culture media containing naturally sterile uncooked protein 

 have made possible the cultivation 

 of microbic forms not cultivable on 

 other media. Many microbes 

 which may also grow on cooked 

 media do much better on those con- 

 taining uncooked protein. It would 

 seem that media of this kind are to 

 play an important part in the fur- 

 ther development of our knowledge 

 of pathogenic micro-organisms. 



Collection of Sterile Blood. A 

 few drops of blood may be obtained 

 from the ear lobe. The skin is 

 cleaned with soap and alcohol and 

 then dried perfectly with sterile 

 cotton. It is punctured with a ster- 

 ilized lancet and the blood quickly 

 transferred to the surface of an agar 

 slant by means of a platinum loop 

 or a sterile capillary pipette. It 

 should be incubated before use to 

 insure sterility. 



Larger quantities of sterile 

 human blood may be obtained with 

 far less danger of contamination 

 from the median basilic vein 

 other large vein at the 

 i The skin is washed, disinfected 



with alcohol and bichloride and dried. An elastic bandage is 

 applied about the arm to distend the veins. A sterile needle 



FIG.. 36. Pipette with needle at- 

 tached for drawing human blood 

 or from a vein for use in culture media. 

 The glass rod inside is used to defi- 

 elbow. brinate the blood. 



