Buttons appear attached to walls, with a green button to activate it.
Buttons appear in many levels of the Test Subject series, and will activate or deactivate a certain object or objects.
To activate buttons, they need to be shot with a blue proton bullet. An orange enzyme bullet will not work even though it is probably a reverse engineered version of blue proton bullet.
There are two types of buttons: deactivation buttons and switch buttons.
- Main article: Deactivation buttons
- Main article: Switch buttons