Here's my following explanation for why denser molecules end up further away from axis of rotation in a centrifuge (i got this from my other account on physics stack exchange - yug)
A centrifuge separates dense molecules from less dense molecules in the following manner.
The centrifuge provides a certain amount of centripetal force, y. centripetal force is given by m * centripetal acceleration. The only way to increase the centripetal force is to increase mass (the magnitude of centripetal acceleration is a constant value provided by the power level of the centrifuge).
Therefore, the heavier the mass = the greater centripetal force needed. Now we also know that centripetal force is the force that pulls something inward in a centrifuge.
However the "y" centripetal force is not enough to provide for the centripetal force required by heavier mass. Therefore, there is not enough inward pull for the heavier mass and so, the heavier mass stays the furthest away in the test tube from the axis of rotation. This is how centrifuges work in separating substances of different densities.
Is this explanation correct? because other sites said the phenomenon occured due to heavier molecules having a greater tangential velocity. I have a feeling I went wrong when I assumed centripetal force to be constant...