Many of the larger molecules have something in common with dolls - movable limbs. Physicists at the Fritz Haber Institute of the Max Planck Society in Berlin can now sort molecules according to the direction in which their "arms" and "legs" point. Normally, it is almost impossible to distinguish between these conformers - molecules with different orientation - and, in any event, molecule limbs usually flap about wildly. Nevertheless, orientation is important for biomolecules: they can only do their job when they point their limbs in the right direction.