Gene Tonics are special serums made from processed ADAM that introduce modified stem cells into the body, allowing for genetic modification and mutation, giving the user what some might call "super powers". In BioShock, Jack is able to choose from a vast selection of Tonics to equip. With Tonic Slot upgrades, the player can equip up to eighteen Tonics, which can be swapped at a Gene Bank. Tonics have three classifications, and only six Tonics per classification may be equipped at one time. Tonics are found in Rapture or purchased at Gatherer's Gardens.