16 



of the conjuyate with membrane receptors for Con A occurs 

 and if the interaction leads to endocytosis of the conju- 

 gate. The mechanism of toxicity (if any) of the conjugate 

 will be evaluated by the use of a Con A resistant CHO 

 mutant and an a-amanitin resistant rat fibroblast cell. 

 These cells will differentiate Con A cytotoxicity, antic- 

 ipated to be minimal with short exposure times and low 

 concentrations, from toxicity due to the amanitin portion 

 of the conjugate. 



