I would like to investigate brassinosteroid activity of crude plant extracts but cannot reach the original paper of Wada et al 1981. Does somebody have experience with this assay? Is there some other assay for detection of brassinosteroid activity that does not require dwarf mutants? I have an experience with extraction and physiological activity detection of other plant hormones, but have never worked with brassinosteroids. What solvent is the best for brassinosteroid extraction from plant tissues (grown in vitro)?