226 EARL W. FLOSDORF 



globin solutions were first deoxygenated by repeated evacuation of all 

 gases, so that over 99% of the oxyhemoglobin was changed to re- 

 duced hemoglobin, the reduced solutions could then be frozen and 

 dried in ampules and the dried hemoglobin kept in vacuo for months 

 without methemoglobin formation. In redissolving the reduced 

 hemoglobin it was necessary to prevent even momentary access of 

 atmospheric oxygen to the dried material before it was dissolved or 

 methemoglobin was formed. After the reduced hemoglobin was in 

 solution oxygenation did not inactivate it and the solution was stable 

 in air. At 4°C. the solution could be kept several weeks without 

 significant change. 



6. Storage and Use of Products 



During storage of dried cultures ordinary refrigeration at about 

 5 to 8°C. is used. This is not essential in all cases, but carrying out 

 systematic studies of the effect of temperature on storage of the many 

 hundreds of strains and different species of organisms of interest is 

 almost prohibitive. Accordingly, it is safest to rely upon refrigera- 

 tion, particularly since the volume of such samples is so small. 



For removing the dry organisms, the stem of the all-glass container 

 may be scratched with a file in the usual fashion. Before breaking 

 the glass tip, the container is wrapped with a cloth impregnated with 

 antiseptic to prevent the spreading of dry organisms as air rushes in. 

 Excess antiseptic should first be squeezed out of the cloth, however, 

 to avoid sucking the liquid into the container when the vacuum is 

 broken. Sterile water is then added. With a small loop, the proper 

 culture medium, either liquid or solid depending upon circumstances, 

 is inoculated. A somewhat longer incubation period may be required 

 to obtain satisfactory growth of the first culture generation. 



F. SOME OUTSTANDING ACCOMPLISHMENTS 



1. Virus Research and Distribution of Vaccines 



Quick-freezing for storage, and freeze-drying for preservation of 

 viruses in distribution as viral vaccines has been employed with suc- 

 cess. Freeze-drying has been applied to vaccinia virus, rabies {9), 

 canine distemper {11), influenza, herpes simplex, laryngotracheitis 

 of fowls, Rous sarcoma, hog cholera, rinderpest, yellow fever, and 

 other viral vaccines, some of them for practical distribution on a fairly 



