like i know for proteins bigger than 5 kd will start to elute immediately after the void volume which is the volume occupying the spaces between the beads right? so if i am putting 1 ml the protein start to elute after 1.5 ml if it was 0.5 ml its gonna start to elute after adding two ml after loading the sample if i am loading 2.5 ml then immediately after the sample loading for PD-10 columns but what about small molecules? at what fractions after the void volume they elute saying i am collecting 0.5 ml fractions? also what is basically the differences between the PD products they use the same beads just differ in how much they are adding?