Table 1

Attempts to derive vincristine-resistant derivatives of the cell line RD in the absence and presence of various agents. Duration of attempt represents the time between seeding the first flask and discarding the last flask

Agent presentNo. of attemptsAverage duration of attempts (days)No. of resistant cell lines obtained
None6523
PSC83325340
VX71018450
XR957611170
CGP412515471
Indomethacin4311
Dexrazoxane2431