Similarly, polyaniline (PANI) has multiple oxidation states referred to as leucoemeraldine, emeraldine, and pernigraniline. Leucoemeraldine, the fully reduced state and pernigraniline, the fully oxidised form, are poor conductors, even when doped with acid. Emeraldine, the half-oxidised form is considered the most useful form as it is highly stable at room temperature. It comes in two forms: