[Detection of antibodies neutralizing the endotoxins of gram-negative bacteria using the liposomal potentiometric...

For the first time the study of the indicator system consisting of sensitized liposomes with NaF incorporated as a marker and a fluorine-selective electrode has been made and, as a result, the possibility of the potentiometric determination of the immune lysis of liposomes in the presence of complement and specific antibodies has been demonstrated. The dissolution of the lipid components (Re-chemotype glycolipid and lipid A) in the bilayer matrix obviates the necessity for converting lipid antigens into the water-soluble state in the process of serological tests. As compared with other methods, the liposomal potentiometric method for the determination of Re-chemotype glycolipid and lipid A is highly sensitive (20-40 ng/ml), rapid, technically easy to perform, cheap and does not require large volumes of samples. The disadvantages of this analytical system are the instability of liposomes and the diffusion of fluorine ions from the internal aqueous phase of vesicules. For this reason the immunoassay can be made only within 12 hours after the preparation of sensitized liposomes incorporating the marker.