Treatment

CI at ED_{50}

CI at ED_{75}

CI at ED_{90}


Xrays + wortmannin

+

+++

+++

Xrays + CisPt







Xrays + vinblastine







Vinblastine + wortmannin

±

+++

+++

CisPt + wortmannin







CisPt + vinblastine







 CI < 1, = 1, and > 1 indicates synergism, additivity and antagonism, respectively. More precisely, symbols +, ++ and +++ describe slight synergism (CI between 0.85 and 0.90), moderate synergism (CI between 0.7 and 0.85) and synergism (CI between 0.3 and 0.7), respectively. Symbols , ,  and  indicate slight antagonism (CI between 1.10 and 1.20), moderate antagonism (CI between 1.20 and 1.45), antagonism (CI between 1.45 and 3.3) and strong antagonism (CI > 3.3), respectively. Nearly additive effects (CI in the range 0.90 and 1.10) are represented by the symbol ±. ED_{50}, ED_{75} and ED_{90} indicate 50%, 75% and 90% inhibition of growth, respectively. Equipotent amounts of the two agents were combined. In most experiments employing Xrays, various ratios were tested. Each CI determination resulted from at least three independent experiments evaluating at least five different doses or dilutions of the two agents.