Is there some logic to how SC, SD and CSM yeast dropout media differ from each other? I have encountered these three formulations in Sunrise Science Products' catalog, and it appears that the composition differs quite a bit, but I couldn't find any information on what the purpose of these media is.
Obviously, any nutrients that are "dropped out" (e.g. -Ura) will select yeast cells on the basis of that marker. However, what about SD-Ura, SC-Ura and CSM-Ura?