A chemical reagent that reacts with and modifies chemically the tryptophan portion of protein molecules. Used for 'active site' enzyme studies and other protein studies. Sometimes referred to as Koshland's reagent.

Synonyms: Reagent, Koshlands, Koshland Reagent, Reagent, Koshland, Koshland's Reagent I, Phenol, 2-(bromomethyl)-4-nitro-, 2-Hydroxy-5-nitrobenzyl Bromide, Koshlands Reagent I, 772-33-8, Koshlands Reagent, Koshland Reagent I, 2 Hydroxy 5 nitrobenzyl Bromide, Reagent I, Koshland's