Optimisation and establishing of serological methods for the potency testing of immunoglobulins against Clostridium tetani-toxin

The quality control of human tetanus immunglobulin requires animal experime nts according to European Pharmacopoeia monograph 398. The potency estimati on has to be done in a toxin neutralisation test in mice (MNT) or guinea pi gs. Immunoassays could also be used if they show a suitable sensitivity and specificity. The first results of our study verify that an indirect enzyme linked immunosorbent assay (ELISA), a rocket immunelectrophoresis (RIE) an d a toxin binding inhibition test (ToBI) could be used as serological alter nativ methods to the MNT Studies on the reproducibility of the in vitro met hods resulted inter-assay coefficients of variation between 2 and 27%. The ELISA is more sensitive (limit of detectability: 0,005 IE/ml) than the ToBI (0,04 IE/ml) and the RIE (5 IE/ml). The transferability of the ELISA to ot her labs is proofed. The transferability of the RIE and the ToBI will be te sted in the near future.