help with HCT116 granulated - (May/15/2012 )

hi all,
I am working on HCT-116 colorectal cancer cell line got from a bank cell which was adapted in DMEM but they told me to buy MCcoys's medim by mistake so I began to adapt them by 50% DMEM and 50% Maccoy's . However, after 2-3 passage they began to change their morphology and now with only maccoys's
+ 10% fbs they have got granulated , clamped and aggregated and even some times giant cell with low rate of growth. I wonder if this changing is because of new medium of it can be caused by infection or any thing else? what is your suggestion to revive and make them normal?

Thanks in advance,

It sounds like the cells do not like the change of medium. If the company that sold you the cell line mis-informed you, then you should be able to get a fresh vial of cells from them and start them off in the correct medium.

For adaptation of a cell line, it is best not to do it quickly - you need to change the proportion of old medium (e.g. DMEM) to new medium (e.g. McCoy's) slowly, such that you might start off with 90% DMEM: 10% McCoy's, then after a passage or so, change that to 80% DMEM: 20% McCoy's... This should help prevent the granulation and presence of senescent cells (the big ones you are seeing, but don't be surprised to see some of these anyway, there are always a few in any cell population).

I grew my HCT116 in DMEM, 10% FBS and 0.5% gentamicin.