title: Letter: A new histochemical method for the demonstration of tissue tryptophyl units by 2-acylation and ring closure.
mesh_terms: D000215:Acylation; D000818:Animals; D002919:Chymotrypsinogen / Q000032:analysis; D006224:Cricetinae; D005069:Evaluation Studies as Topic; D006651:Histocytochemistry; D006801:Humans; D008722:Methods; D008856:Microscopy, Fluorescence; D010179:Pancreas / Q000032:analysis / Q000166:cytology; D010455:Peptides / Q000032:analysis; D011506:Proteins / Q000032:analysis*; D014364:Tryptophan / Q000032:analysis*
chemical_list: D010455:Peptides; D011506:Proteins; D014364:Tryptophan; D002919:Chymotrypsinogen