An enzyme immunoassay for the determination of taxol and taxanes in Taxus sp. tissues and human plasma.

A rapid and sensitive indirect competitive inhibition enzyme immunoassay (CIEIA) method has been developed for quantitating taxanes in extracts of Taxus brevifolia Nutt. tissue and in human plasma. High titer rabbit polyclonal antibodies (pAb) were raised against a conjugate of 7-succinyltaxol and keyhole limpet hemocyanin. The presence of taxane analyte competitively inhibited the binding of the rabbit anti-taxane pAbs to a 7-succinyltaxol-bovine serum albumin solid phase coating antigen. The CIEIA detected taxol and cephalomannine in concentrations as low as 0.3 ng/ml (3.5 x 10(-4) microM), but did not detect baccatin III or 10-deacetylbaccatin III at concentrations below 1000 ng/ml (1.7 microM and 1.8 microM, respectively). This method is useful for estimating the taxane content of T. brevifolia extracts and may be useful for monitoring the taxol plasma level of taxol-treated patients.