Hello Foram

First and foremost you should obtain the IC50 value of Dox in both the cell lines namely MCF-7 and MDA MB 231. You can do that by treating the cell lines with increasing concentration of Dox say ( 25 nM to 6000nM). Then check for cell viability using the Sulphorodamine B (SRB) assay. Treat the cells with Dox when they are 80% confluent.

Once you establish the IC50 value for both MCF-7 and MDA MB 231, treat the cells initially with their respective IC50 concentrations in serum free medium for a few days (2-3 days). Wash the cells with phosphate buffered saline and continue to culture the cells in their normal media containing 10% FBS. Repeat this procedure for two to three passages. Then try increasing the Dox concentration for both the cell lines and repeat the same steps as done for the IC50 concentration.

Please note this process will take some time at least 4 to 6 months to induce Dox resistance.

All the best!

Hello, Foram!

You can see this publication, please:

Article Discrimination of the Effects of Doxorubicin on Two Differen...

Thank you so much for sharing the protocol.Once resistant is induced,then should I suppose to grow the cells in media containing doxorubicin +10% FBS or media containing only 10% FBS Malcolm Nobre

Hello Foram

Once resistance is induced you should grow the cells in media containing doxorubicin and 10%FBS. This is to avoid the cell line from losing its resistance to doxorubicin

Thank you.

Malcolm Nobre Do passage number of parental cell line matters for the induction of resistance?