I am using gibco RPMI Medium 1640 (1X), [+] L-glutamine, [-] Phenol Red with 10% FBS to grow the MDA-MB-231 (triple-negative) cancer cells in 5% CO2 and 37c temperature. I always seed 20%, however, upon observation after 38hours (doubling time), I am observing that my cells are not growing well as they should be, they show only 10% or sometimes even less than 10% confluency. The same cells are growing fine in regular RPMI media with 10% FBS. Any suggestions regarding this would be appreciated. Thanks.
Hello Maria Arshad
Does your medium namely, gibco RPMI Medium 1640 (1X), [+] L-glutamine, [-] Phenol Red with 10% FBS contain sodium bicarbonate?
Since most pre-mixed powdered media are manufactured without sodium bicarbonate, this buffer must be added in appropriate concentration during liquid media preparation either as a sterile solution (x ml of 7.5% Sodium Bicarbonate Solution) or as a powder (x gram of Sodium bicarbonate) prior to filtration which will be mentioned by the manufacturer.
The most common buffer used in mammalian cell culture is sodium bicarbonate. The sodium bicarbonate buffered media becomes sensitive to carbonic acid formed by the concentration of CO2. As long as the level of CO2 is controlled, the pH of the media can be maintained.
To allow cell cultures to grow, the pH value should be balanced and stable. Starting values of pH 7.2–7.4 are ideal for nearly all mammalian cells.
I hope this helps.
Best.
Hello Maria Arshad
Apart from what Malcolm Nobre suggested, another aspect that you could look into is the growth medium. Although RPMI and L'15 media are widely used to grow MDA-MB-231, DMEM (High Glucose) + 10% FBS is a much better option for faster growth (media change 2-3 times a week). And this might just solve your problem with the lower confluency of cells.
Thanks, everyone for your suggestions, I increased the seeding percentage to get the desired results and so far it's working for me.