In the currently accepted mechanism, the pararosaniline and bisulfite combine to yield the "decolorized" adduct with sulfonation at the central carbon as described and shown. The free, uncharged aromatic amine groups then react with the aldehyde being tested to form two aldimine groups; these groups have also been named for their discoverer as Schiff bases (azomethines), with the usual carbinolamine (hemiaminal) intermediate being formed and dehydrated en route to the Schiff base. These electrophilic aldimine groups then react with further bisulfite, and the Ar-NH-CH(R)-SO3− product (and other resonance-stabilized species in equilibrium with the product) give rise to the magenta color of a positive test.[4] Prior formation of classical bisulfite adducts of the tested aldehyde may, when the adducts are stable, give rise to false negative tests such as in the case of testing for the aldehydic terminus of glucose.[4] Schiff's reagent on reaction with Acetaldehyde gives pink colour.