procedure for the diagnosis of cancer by bestemning of nervaron of cancer linked polypeptidantigen (capa)

摘要

To obtain a tumour polypeptide antigen, initially material with tumour polypeptide antigenic activity is homogenised in a liquid at a temperature not exceeding 0 DEG C. The solids are removed from the mixture of liquid homogenate and solids directly or after treatment with an organic solvent in the cold. The solids are extracted with an alkaline aqueous solution. The extract is filtered through a filtration gel of the molecular sieve type in bead form which permits fractionation of compounds with a molecular weight in the range from 10,000 to 20 x 106, the gel is eluted and the fraction with a molecular weight of 10 x 106 to 20 x 106 is obtained. The resulting fraction is purified by chromatography. The fraction having antigenic activity is obtained and subjected to isoelectric precipitation by adding acid until the solubility of the polypeptides reaches a minimum as a consequence of the presence of the polypeptide molecules in the form of zwitterions. Subsequently, the polypeptide antigen is further purified. The resulting tumour polypeptide antigen can be used for the preparation of antibodies which are monospecific for the polypeptide antigen.