<prompt> Sakaguchis reaction is specific forTyrosineProlineArginineCysteine  <response>: Sakaguchis Test for Arginine : Free arginine or arginyl residues in proteins react with alpha-naphthol and alkaline hypobromite to give bright-red color. This is due to the guanidium group.Reference: Vasudevan 7th ed, pg 32 