well , the process take time a little bit..the most important factors are the cell number and doxorubicin concentration .so first you start from low conc of drug around 1 ng/ml incubate for 24 hours then change the medium for 2-3 days and in my 5 days sometimes moving to the higher conc and so on and after you reach the higher conc at the end of the scale you should always keep the cell with drug to dtermine the resistence (10000ng/ml ) in case doxorubicin in MCF7 ...

well , the process take time a little bit..the most important factors are the cell number and doxorubicin concentration .so first you start from low conc of drug around 1 ng/ml incubate for 24 hours then change the medium for 2-3 days and in my 5 days sometimes moving to the higher conc and so on and after you reach the higher conc at the end of the scale you should always keep the cell with drug to dtermine the resistence (10000ng/ml ) in case doxorubicin in MCF7 ...

Dear Carol Panis,

I also tried develop the Tamoxifen Resistance in MCF-7 cell line and i struggled very much to establish a method. Mainly developing of the resistance cell line to an anticancer agent is possible but it will take long time (in my case it is 6 months). In development of anticancer molecule resistant cell line first you have to establish the IC50 value of the substance in the respective cell line under the laboratory conditions.

After that initially treat cells with IC50 concentration at 80% con-fluency in absence of Fetal Bovine Serum (FBS) then incubate for 2 days and wash the cells with media and grow them in media+10% FBS . Maintain this procedure upto when the cells resistant to particular concentration. After gaining the resistance increase the concentration and repeat the same procedure.

Anyways it will take long time but be careful while handling the cells there are possibilities to get contaminated.

All the best and regards