Production of monoclonal antibody against a major purgative component, sennoside A, its characterization and ELISA

For immunization, sennoside A was conjugated with bovine serum albumin. The hapten number in an antigen conjugate was determined to be five by matrix- assisted laser desorption/ionization TOF mass spectrometry. A hybridoma sec reting monoclonal antibody against sennoside A was produced by fusing splen ocytes immunized with sennoside A-bovine serum albumin and a hypoxantine-am inopterin-thymidine (HAT)-sensitive mouse myeloma cell line, P3-X63-Ag8-653 . Weak cross-reactivities occurred with sennoside B which is a stereochemic al isomer, and a monomer of sennoside A, rhein, but no cross-reactivities w ere observed with other related anthraquinones and phenolics. The full rang e of the assay extends from 20 to 200 ng ml(-1) of sennoside A. Good correl ation of sennoside A concentrations in crude extract of rhubarb between ELI SA and HPLC methods was obtained. The contents of sennoside A in various rh ubarb roots were assayed by the newly established ELISA indicating a good a greement with the previous reports.