Catalytic antibodies (catabs) are currently produced by three different methods, by the generation of monoclonal antibodies against transition-state analogs of chemical reactions, by the gene technological establishment of a huge library of antigen binding sites, and by the transplantation of catalytic motifs into the antigen binding site. In addition, catabs can be further refined by chemical modification and in vitro mutagenesis. Disadvantages of the new technology are the mostly empirical production of catabs, the low affinity, and the slow turnover rate. Advantages are the immense variability of the antigen binding site and the potential of general applicability of the technology due to the conserved structure of the antigen binding site.