Schiff's reagent A reagent used for testing for aldehydes and ketones; it consists of a solution of fuchsin dye that has been decolorized by sulphur dioxide. Aliphatic aldehydes restore the pink immediately, whereas aromatic ketones have no effect on the reagent. Aromatic aldehydes and aliphatic ketones restore the colour slowly. It is named after the German chemist Hugo Schiff (1834–1915).

Schiff's reagent A reagent, consisting of fuchsin bleached by sulphurous acid, that produces a red colour upon reaction with an aldehyde.

Schiff's reagent A reagent consisting of fuchsin bleached by sulphurous acid that produces a red colour upon reaction with an aldehyde.