A sample of cells will be provided and I must test whether or not there is a difference between the top. middle and bottom of the solution (the theory being that the cells may settle out of solution)

The RSD of the method used for counting the number of cells is 15% and the average number of cells is expected to be approximately 1E+6 cells/mL.

Is there an easy(ish!) way I can determine how many samples I would need to take from each sampling point to show that there is/isn't a difference between them?

Thanks for any help!