I am working with lymphatic endothelial cells and trying to test effect of few chemicals, on LECs by wound healing scratch assay. My confusion is, if I have 4 different chemicals cited in different literature to be used for cell culture studies, in different concentration let's say, if A is 10 um then B 25, C may be 100 and D 400um. What would be ideal concentration if I want to compare the effect of these individual chemical on one cell type. Should I be choosing one from literature individually or a standard concentration for all to be used, to make a comparison.