What does the term "autofluorescence" refer to?

The term "autofluorescence" refers to the natural fluorescence of cellular components. This phenomenon occurs when certain molecules within biological tissues, such as metabolites, proteins, or coenzymes, emit fluorescence without the need for any external fluorescent labels or chemical tags. Autofluorescence is particularly common in tissues where compounds like NADH, flavins, and various pigments exist.

Understanding this concept is crucial in contexts like microscopy and imaging, where autofluorescence can sometimes interfere with the visualization of specifically labeled structures, including those tagged with fluorescent proteins like GFP. Recognizing the inherent fluorescence of cellular components allows researchers to interpret their observations correctly and differentiate between background signals and specific fluorescent markers.