Antiserum production purification

Monoclonal antibodies can be raised to defined antigens and provide very specific probes (17) practical protocols are provided by Cuello and Cote (18). It is important to keep in mind that monoclonal antibodies— in spite of their monospecificity—do not circumvent the problem of crossreactivity with imi-dentified tissue antigens. The same rigorous testing needs to be performed for monoclonals. To increase the specificity of polyclonal antisera, one can perform affinity purification and/or separate IgGs from the whole serum. For such purifications, commercial columns are available. Details on antiserum/antibody production have been given in many accounts fe.g., 13,18-23). 

By help of this antiserum, that contained crossreacting precipitating antibodies ( short ab ) against the native conformation of S, the purification of S and the production of S-free CF 4 was monitored by elefctroimmunodiffusion. It turned out that the isolation procedure of Nelson,Karny,1976 and Younis et al.,1977 yields only 3-4% of the initial amount of S. The fraction discarded after the pyridine step contained 4 times more 8 than the one used for purification. If the separation after pyridine treatment was done on Sephacryl S 200 in the presence of urea instead, (fig. 1), about 35% yield of nearly pure 5 fractions could be obtained. They were further purified on a second Sephacryl column or on DEAE-cel-lulose. Also the antiserum 167 against this urea 8 crossreacted with the native conformation. 

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