EXAMINATION OF SHELLFISH 263 



Transportation of Samples. When the time between 

 the collection of the sample and its examination exceeds 

 3 hours, or if the outside temperature is above 50° F., the 

 sample shall be thoroughly refrigerated by means of ice 

 placed around, but not in, the sample jars. 



Technical Procedure. The bacteriological examination 

 shall be begun as soon as possible after taking the sample. 

 The sample shall be thoroughly shaken at least 25 times 

 immediately before opening. 



Bacterial Counts. The procedure specified for oysters 

 in the shell shall be followed: 



Determination of Bacteria of the Bacillus Colt Group. 

 The procedure specified for oysters on the shell shall be 

 followed, but attention is called to the fact that higher 

 dilutions than ^^ c.c. are usually required. TripUcate 

 fermentation tubes shall be inoculated from each dilution 

 of the sample. 



Sfatement of Results. The results of the bacteriological 

 examination of the opened oysters, or shucked stock, shall 

 be expressed in the same way as that specified for oysters 

 in the shell, except that in the calculation of B. coli rating 

 the values for the results of the positive fermentation tests 

 after confirmation shall be recorded for each of the inocula- 

 tions of each dilution. In order that the rating from these 

 tripUcate tests may be compared with that obtained from 

 testing 5 oysters in the shell, the sum of the values for 

 the triplicate tests shall be multipUed by f . If, instead, the 

 sum is divided by 3, the result will give approximately the 

 number of B. coli per c.c. 



Clams and Other Shellfish 



The methods for examining clams and shellfish other 

 than oysters shall be those given above. Certain modi- 

 fications are necessary in the method of handling the samples 

 and the opening of the shells, etc. 



