TSA labeling of proteins. (A) Chemical structure of tyramide-FITC and the labeling of proteins. (B) Western blot (WB) after TSA labeling with either tyramide-biotin or tyramide-FITC. Cell lysate without TSA reaction and a TSA reaction without primary antibody were included as controls. (C) Gel picture showing total protein staining of 0.5% of the input lysate after TSA reaction compared with 50% of the total proteins pulled down. (D) Western blot comparing FITC-labeled proteins as in C.