The DNA Cloner allows to clone mobs. But a Insulated Helix of the mob you want to clone in the slot at the bottom.
You can also apply a custom DNA to the spawned mob by putting a Syringe with the DNA in to upper slot.
But finally, the machine needs one Insulated Cell to spawn one Mob. You can store these cells in the 9 solts at the right side.
As every machine it requires energy to run. See energy supply for more information on how to power machines.