Several histological stains are used to identify catecholamines in tissue sections. The _Falck-Hillarp method_ employs formaldehyde-induced fluorescence to visualize catecholamines. Immunohistochemistry can also be used to detect specific enzymes involved in catecholamine synthesis, such as tyrosine hydroxylase. Additionally, _chromaffin reaction_ using chromium salts can be employed to stain chromaffin cells.
