Time course/kinetics - (Sep/19/2012 )

HI everyone,

I've done several kinetics stimulating cell lines for up to 72h (6h, 12h, 24h, 48h, 72h; one cell culture flask per timepoint and stimulation). Now, I was told, I did it in a wrong way. I started with different cell concentrations:
6h, 12h, 24h 500000/ml
48h 200000/ml
72h 100000/ml

Now my PI told me, that I can't compare the different timepoints, because they had different growth conditions.

Has anybody an idea how to do kinetics correctly. Since I use suspension cells, roller bottles might be a solution to create perfect and similar growth conditions, having only one starting culture and taking out samples at the different timepoints.

Looking forward to your help.
Tweety

I usually plate them at the same time in the same density and take a flask/petri dish for one time point. But, I do a time course of the growing (test different starting densities) to be sure I have enough cells for the first time point and that they do not all die of over-crowding in the last time point.