Autofluorescence spectroscopy for diagnosis: from cells to tissues

Cells and tissues, upon excitation at suitable wavelengths, give rise to a fluorescence emission – autofluorescence – due to the presence of endogenous fluorophores. Autofluorescence emission properties are closely dependent on the amount, topological distribution and microenvironment of the endogenous fluorophores, in strict relationship with the metabolic processes and in the histological organization in which they are involved. Alterations of the physiological state or rising of pathological conditions result in changes of biochemical composition and/or structural organization of the biological substrates, that can affect the autofluorescence emission properties. As a consequence, analysis of autofluorescence signals can be exploited to obtain information on the morphfo-functional conditions of the biological substrate, suitable for diagnostic purposes. The endogenous fluorophores mainly responsible for the autofluorescence emission of cells and tissues are here briefly described, along with an overview of diagnostic applications, mainly as to our experience is concerned.