Abstract
A radioimmunoassay for the determination of pmol amounts of the indole alkaloid ajmaline
has been developed. The antiserum was raised against a conjugate of ajmaline hemisuccinate-bovine
serum albumine. The measuring range of the assay extends from 0.05 to 20 ng of ajmaline,
and as little as 150 fmol may be detected. The antiserum is highlyspecific for ajmaline,
with only the ajmaline-isomers sandwicine, isoajmaline, and the unnatural 17-monochloroacetylajmaline
showing substantial cross reactivity. This assay allowsthe rapid, sensitive and precise
determination of ajmaline in unpurified extracts of whole plants as well as of cell
cultures. The distribution of ajmaline in Rauwolfia plants, as well as the ajmaline production of Rauwolfia cell cultures, has been investigated. The assay was used for studies to improve the
Rauwolfia cell culture medium and a preliminary survey on the variability of ajmaline production
in a population of Rauwsolfia cells is given.
