why separation does not happens in stacking gel

Question

Why separation doesn’t takes place in stacking gel in gel electrophoresis and why does separation completed in the separating gel?

Answer 1

Stacking gel has a much greater pore size, and is merely employed for stacking (or arranging one over other) the samples so that they can be solved in separating gel easily. Because the separating gel has a best possible pore size so the samples separate through the molecular sieving effect of resolving gel that is not present in case of stacking gel.