| abstract |
The present invention relates to a process for the preparation of cytotoxic products by causing the formation of a covalent bond by means of a disulfide bridge between a cytotoxic compound, ricin A chain, and an antibody, immunoglobulin or a fraction thereof. immunoglobulin specific for a given antigen, carried by the cells that are to be destroyed, characterized in that the ricin A chain is purified by chromatography until, after cooling, crystallized A chain is obtained and the products obtained according to said process. |