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interpretation of results - cell growth assay (Dec/16/2007 )


Would someone please help me with the interpretation of the cell growth assay?


I am struggling to describe the results. wacko.gif

This experiment is a [3H] thymidine incorporation, where cell incorporates thymidine during proliferation.

The purpose of this experiment is:
(1) to determine the combination effects of chemical A and chemical B on a breast cancer cell line
(2) since both chemical are quite expensive, the combination may reduce the concentration require to kill the cancer cell.

I know that when the concentration of chemical A and Chemical B increased, the level of inhibition increased (or the level of proliferation decreased).
The combination of these two chemical produced synergistic effect, according to two-way ANOVA.

Q1. Do I talk about IC50?
Q2. Do I talk about each individual line? or as a whole?
Q3. Do I talk about the difference in the concentration?

Thanks in advance.

Minnie Mouse

-Minnie Mouse-

at the first glance:

change the y-axis to inhibition instead of %of control cell vitality. you talk about inhibition too when you tell us what this experiment is about dont you? thats because its much more common and more easy to understand. really its easy to explain to someone why a graph that goes up is good but its complicated to explain why a graph that goes down is good.

and please fix the min and max of the y-axis scale to 0 and 100%. i know excel does this 120% default parameter but there is no such thing as more than 100% vitality (or less than 0% inhibition after you reversed it).

at the second glance:

B is ng/mL and A is µg/mL. is this on purpose? when those chemicals are the same price but B is 3 orders of magnitude more powerful in inhibiting cancer cells why bother with A anyway?

Q1. Do I talk about IC50?

yep. the IC50s seem to be about 9µg/mL for A and about 45ng/mL for B.

Q2. Do I talk about each individual line? or as a whole?

you could show another graph that shows the effect of B without A. Then show a graph that shows the inhibtiting effects of A without B. And finally the merged graph that you have here.

Q3. Do I talk about the difference in the concentration?

yes i mentioned earlier and i would definitly stress that B is far more effective. just look at the IC50s.


Thank you very much, coastal. smile.gif

-Minnie Mouse-