NORTHEY 



While the original aim of this investigation was to determine whether 

 or not differences exist in response to antigenic stimulus in "cold 

 stressed" animals as opposed to "normal" animals following im- 

 munization with various selected microorganisms, preliminary ex- 

 periments indicated that these systems were not sensitive enough, 

 nor did they possess a high degree of specificity. Early experiments 

 were designed to measure qualitative and quantitative differences 

 in response to the injection of various selected microorganisms 

 such as Salmonella typhimurium and Diplococcus pneumoniae. 

 Analysis of the sera collected from animals challenged in this man- 

 ner proved to be difficult in that as the gel diffusion technique best 

 serves as a measure of the "soluble" antigen content of a microbial 

 suspension, the degree of sensitivity which could be attained using 

 microbial anti- microbial systems was inadequate to detect differ- 

 ences in the "cold stressed" and control animals. Because of the 

 high degree of reactivity inherent to antigen- antibody systems in- 

 volving complex soluble protein antigens, a number of systems in- 

 volving these antigens were selected for investigation. As a result, 

 the original experimental protocols were modified to include a num- 

 ber of new systems which are of sufficient complexity and sensi- 

 tivity for a study of this t3q3e. These new studies included such pro- 

 tein antigens as human serum, egg albumin (Ea), bovine serum 

 albumin (BSA), and whole bovine serum. These protein antigens, al- 

 though not implicated in the usual "infective process", serve as a 

 reliable index of the degree of sensitivity and selectivity by the 

 antibody forming mechanisms. 



METHODS 



Gel Diffusion 



One of the most sensitive methods of measuring the antibody 

 response is through the use of the gel diffusion technique devised 

 by Ouchterlony (1949). In this investigation a 1 per cent solution of 

 lonagar Number 2 (Consolidated Laboratories, Chicago Heights) 

 was used to prepare the gel. The pattern was cut in the agar using 

 a Fineberg Agar Gel Cutter Number 1802, manufactured by the 



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