Eastern blotting and use of anti-saikosaponin a monoclonal antibodies for detection of saikosaponins

Abstract

Immunochemical assays using anti-saikosaponin a monoclonal antibody (MAb) and so-called Eastern blotting have been established for semi-quantitative analysis of the saikosaponins (SS) SSa, SSb2, SSc, and SSd, which are active constituents of the Bupleuri radix. After crude separation of saikosaponins by TLC, compounds were transferred from the TLC plate to a PVDF membrane where they were oxidized with NaIO4 and, finally, conjugated with bovine serum albumin (BSA). Clear and specific detection and identification of the immobilized saikosaponin–BSA conjugates were achieved by use of the MAbs. Compared with TLC, the Eastern blotting technique for analysis of saikosaponin compounds is a simple method for quality-control monitoring of Bupleuri radix and of Kampo formulations containing Bupleuri radix.