TECHNIQUES 



9-9 



DRYING CULTURES 



Yeast cultures can be preserved indefinitely by the drying meth- 

 od described by Brown (1925). This method is in use in Dr. Bron- 

 fenbrenner's laboratory at Washington University Medical School 



Fig. 9-6 Removing the Cover Glass from the van Tiegham cell 

 Each agar drop contains a small single yeast colony grown from a 

 single ascospore. 



and has been used with considerable success in our laboratory. 

 Blood serum which has been sterilized by filtration is poured on 

 the slant of a young culture (fig. 9-7) with a pipette drawn from a 

 7 mm. glass tube. (The tubes are kept in the cotton-stoppered acid 

 bottle shown in fig. 9-10). The blood serum is stirred around on 

 the surface of the slant and the suspension of yeast cells in serum 



