4-diazobenzoyl biocytin

p-Diazobenzoyl-biocytin chloride is a biotin derivative that can be used for the labeling of tyrosine and histidines in peptides and proteins[1].

[1] Wilchek M, et al. p-Diazobenzoyl biocytin--a new biotinylating reagent for the labeling of tyrosines and histidines in proteins. Biochem Biophys Res Commun. 1986 Jul 31;138(2):872-9. DOI:10.1016/s0006-291x(86)80577-0