A HOMOGENEOUS IMMUNOLOGICAL DETECTION SYSTEM FOR SOMAN USING THE INVITRO PROTECTION OF ACETYLCHOLINESTERASE BY A MONOCLONAL-ANTIBODY

In this study a monoclonal antibody (MAb) based soman detection system was investigated. Since the MAb F71D7 recognizes the pinacolyl group of soman, non-toxic soman analogues are also detected when using an in direct competitive ELISA. This can lead to falsely positive results. T he toxic effect of soman is, however, independent of the pinacolyl gro up. In the described homogeneous enzyme immunoassay (EIA), the inhibit ory effect of soman on acetylcholinesterase (AChE) was combined with i ts specific binding to the MAb F71D7 in order to minimize false positi ve results and enhance the specificity of the detection system. In thi s rapid EIA no incubation or washing steps are necessary, so only time for pipetting and reaction have to be considered. Soman could be dete cted in concentrations of 1.6-25 nM using the EIA. This corresponds to 8 pg soman per 25 mul sample and means that compared to other ELISA s ystems, besides enhanced specificity, the limit of detection could be improved by 3 orders of magnitude.