Same cell line but different growth rate - (Apr/11/2007 )

Hi all,

I have been culturing a normal esophageal epithelial cell line but the growth rate varies sometimes. This makes me uncomfortable.
Usually it takes more than a week to get about 90% confluence but sometimes it gets 90% within 3 days. I wonder if this normal cells have been crosscontaminated with some cancer cells. The medium I use for this normal cell line is keratinocyte SFM with EGF and bovine brain extracts as supplements.

Do any one ever encounter such situation?
Plz share you experience and thx in advance.

Marco

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I aasume you seed the same amount of cells for each passage? Some cells are sensitive to the cell density. It wont grow, or grow much slower when the density is low. Some even go differentiation if cultured at low cell density and giant multinuclei cells appear. I dont know if that is the case for your cells.

tHve you noticed any morphological changes ?

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The cells which grow faster look a bit bigger than that of the slow growing ones. Also they look like those of cancer cells.
I know cell density does have a effect on growing rate. But I wonder if it would lead to such a big difference. Really much faster, I need near 4 week time to get 4 10 cm plate 80% confluence before..

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are you using primary cells? if so, there is always variation lot-to-lot in doubling time, and it can be pretty dramatic.

also, passage when frozen can have an affect on the growth rate of primary cells. the later the passage, the slower the growth...and variation occurs during freezing. perhaps some cells were damaged more by the DMSO than other batches, etc...

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I do not have a clear explanation but it must be anaything that was changed... coating or different plastic culture ware or amount of medium or composition of medium...


the cell line sounds interesting. does it build an epithelium with barrier function? I am interested in those cell line for barrier function studies; I only know renal MDCK cells and colonic Caco-2 cells

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