Major effects on cells grown with 5% FBS supplemented media instead of 10% FBS?

Question

I maintain a few cell lines in the laboratory (industrial R&D) that I use regularly for experiments. I realized today that the media i prepared for the week on monday was only supplemented with 50 mL of FBS into 1 L of DMEM, instead of the usual 100 mL that i usually do. I was in a hurry and absentmindedly didn't add the second 50 mL autopipettor's worth.

My cells are fine morphologically but I think they're growing a bit slower than usual, my guess is due to the 1/2 concentration of all the FBS growth factors, etc. Are there any other effects that would be pronounced in these?

I understand that it will be apples to oranges to do compare results with these cells to, say, an experiment done with a batch of cells grown in complete (10% FBS supplemented) media.

Answer 1

If you were to run a flow-based viability assay (annexin V, live/dead fixable dyes, 7-AAD) or dual-fluorescence count (like acridine orange/propidium iodide, popular method as of late), you might find that more cells are undergoing apoptosis, or an increase in dead cells. I say this because trypan blue often overestimates viability. Your most pronounced effect should simply be a reduction in viable cells or a slower growth curve if you take those data points. Otherwise you'd need to run some test (fair example).

The problem being, these observations vary wildly based on what cell line you're using, lot-to-lot variability of the serum, and reagent handling. For example, the serum was heat-inactivated improperly, medium was degraded, bad lot of serum, and so forth. So take this as a generalization and a good reason to validate your serum lots.