Chem. a colorless solution of fuchsin and sulfurous acid used as a reagent to identify an aldehyde from a ketone from the shade of reddish purple produced, to stain DNA, etc.
See Schiff's reagent in American Heritage Dictionary 4
noun
An aqueous solution of rosaniline and sulfurous acid used to test for the presence of aldehydes.
Origin:
Origin: After Hugo Schiff (1834-1915), German chemist