Ok so I need to create a solution by adding two solutions together with different concentrations.

The final volume needs to be 100 microlitres. So the first solution is a drug whose concentration needs to be 100 micromoles (uM) and this needs to be mixed in with the second solution whose concentration needs to be 4 millimolar.

I think that say if I mix 50 uL of the 0.1 uM first solution with 50uL of the 4mM other solution, the end concentrations of each solution will not be 0.1 uM and 4mM respectively? i think that it will halve right?

So I am wondering how I can put a specific volume or concentration of each of the two solutions initially but in the end after mixing them together keep their respective concentrations as 0.1uM and 4mM?…..

Do I need to add double the end concentration initially?

Would appreciate any help and thanks in advance:)