Using toad oocytes as an ultrasensitive system for estimating the biological activity of trichosanthin.

A sensitive bioassay for estimating the activity of Trichosanthin was developed by using intra-oocyte microinjection as the technique and germinal vesicle breakdown as a marker. The GVBD inhibitory activity assay was million-fold more sensitive than the routinely used abortifacient activity assay. The detectable amount of Trichosanthin ranged from 0.5 to 100 pg. Since the least detectable dose was 0.5 pg, it made the assay suitable to analyse the micro-quantity of pure Trichosanthin used for studying the structure and function of the drug.