Did anyone here use neomycin to kill MCF-7 cells? - (Mar/29/2006 )

Recently, I used neomycin to kill the MCF-7 breast cancer cells. I used 1000ug/ml for 5 passages, the cells still grow well. I am wondering anyone here has the experience about this.
Thanks.

I don't think you're using enough neomycin. I've read papers that use 3mg/mL and 5mg/mL.

Vetticus

I use 2mg/ml for MCF-7 cells.

(I figured out how much to use after I did a kill curve. I highly recommend u do the same. I had trouble killing HeLa cells, until I did a kill curve and found out I have to use 6mg/ml of G418 (neomycin)!)

[quote name='apoptosishead' date='Mar 30 2006, 12:04 AM' post='46118']
I use 2mg/ml for MCF-7 cells.

(I figured out how much to use after I did a kill curve. I highly recommend u do the same. I had trouble killing HeLa cells, until I did a kill curve and found out I have to use 6mg/ml of G418 (neomycin)!)


Thanks a lot!

ps: could youtell me how to do kill curve? thanks.

stormlina

A "kill curve" (as far I define it) is when u titrate the concentration of antibiotics required to kill cells within a period of time. Therefore, in my case I setup a six-well plate with a cell density that will make the wells become confluent in ~6-7days, and I have media with increasing concentration of G418 (i.e. 0, 0.25mg/ml, 0.5, 1, 2, 4 etc). By this method I was able to find out the sensitivities of various cell type to antibiotics (i.e. Saos-2 0.25mg over 9 days, or 0.5 over 6 days (where 100% of the cells in that well were dead); MCF7.. etc...).

I think G418 inhibits protein synthesis. I suspect different cells need different amounts of G418 proportional to the amount of protein synthesis that takes place and ultimately to pass a critical threshold where cells eventually start to die. Threrefore, in the future, I highly recommend doing a kill curve with every batch of G418 (as prescribed in reagent data sheet) and with every new cell type.