At present, several histochemical methods for proteins using fluorescent
dyes and reagents are available. Some of them utilize simple fluorochromes, whereas
others involve preferential fluorogenic reactions with amino acids. Ionic, hydrophobic,
and covalent interactions occur between protein groups and fluorochromes. In addition
to these classical demonstrations of proteins, more selective methods such as immunofluorescence
and detection of enzymatic activity are now widely used in microscopical
studies. Also other macromolecules such as nucleic acids, polysaccharides, etc., can be
visualized by these methods. Detection of macromolecules is also possible with
haptens (i.e. dinitrophenol, biotin, digoxigenin) that are recognizable by suitable
ligands (antibodies, streptavidin), or using labeled lectins, toxins, oligonucleotides, etc.
(see Chapter 4). Fluorescent reactions for enzymatic activity and immunofluorescence
are described in Chapters 14 and 17.
Keywords: Amino groups, Amyloid deposits, Aromatic amino acids, Carboxyl
groups, Catecholamines, Dansyl chloride, Fast blue B, Fast red TR, Furanones,
Indolamines, Isatin, Isoelectric point, Mercury orange, NBD, Phenanthrenequinone,
Sulfhydryls.
