86 BULLETIN 846, U. S. DEPARTMENT OF AGRICULTURE. 



If it is necessary to use a spoon to collect the chips made by a bit, 

 it should be sterilized in like manner. Wipe all utensils thoroughly 

 clean with a cloth before each sterilization. Thoroughly cleansed 

 Mason jars, which have been sterilized in the autoclave with the 

 rubber rings and covers in place, make convenient containers for 

 subsamples. 



The bacteriologist records the general condition of all samples at 

 the time of sampling, specifying the temperature, appearance, color 

 and odor. 



SUBSAMPLES FOR CHEMICAL EXAMINATION. 



The two chemical subsamples are taken in the same way as the 

 bacteriological subsamples, except that sterile instruments and con- 

 tainers need not be used, and at least 1 pound of material is col- 

 lected for each subsample. One of these should be placed in cold 

 storage immediately at approximately 0° F. 



SUBSAMPLES FOR PHYSICAL AND MICROSCOPICAL EXAMINATION. 



These consist of the entire contents of each container, after the 

 bacteriological and chemical subsamples have been removed. 



Liquid Egg. 



Thoroughly mix liquid egg samples with a sterilized utensil, such 

 as a long-handled dipper which has been immersed, including the 

 handle, in alcohol and flamed, after which subsamples are withdrawn 

 for examination. Place the subsamples for bacteriological examina- 

 tion in sterilized containers. Keep a record of the general condi- 

 tion at the time of sampling, specifying the temperature, appearance, 

 color, and odor. 



Shell Eggs. 1 



whole egg. 



Clean each egg 2 with brush, soap, and water, and immerse for 10 

 minutes in a 1 : 500 mercuric chlorid solution. Transfer with sterile 

 crucible tongs to a small conical graduate or other convenient holder, 

 acute pole uppermost. Remove the mercuric chlorid and dry the 

 egg by pouring over it first alcohol and then ether. Scorch the 

 acute pole to kill spores that may remain. Immediately remove 

 the egg from the graduate, holding it near the blunt pole, turning 

 the acute pole down. The hands of the operator should have been 

 thoroughly greased with vaseline to avoid contamination by bac- 

 teria that might rub off during the handling of the eggs. Hold the 



1 These methods are included because they were used in the preparation and examination of samples 

 in the laboratories. • 



2 Adaptation of method of Bushnell and Maurer, Kansas Agr. Coll. Bui. 201. 



