Immunocytochemical demonstration of 5-hydroxytryptamine in gastrointestinal endocrine cells

We have been able to demonstrate 5-hydroxytryptamine in the enterochromaffin cells of the mammalian gastrointestinal tract, using a highly specific antiserum. Conventional histochemical techniques for identifying amines as cell markers can thus be replaced by more reliable and sensitive immunocytochemical methods. This has been facilitated by the use of p-benzoquinone as fixative which has been shown to preserve the localization and antigenicity of amines, as well as peptides.