If the Alchemist’s Lab is installed in your Hold, you can use the Lab as an advanced Alchemist’s Kit, granting you a +5 bonus to the tool skill check.
Potions and poisons made in the Alchemist’s Lab have a +1 bonus to their DC if they have one and you choose to do so.
Healing potions made in the Alchemist’s Lab heal an additional amount equal to the tool skill check bonus used to make the potion.