自体荧光即生物体内一些物质不需外源荧光染料染色即可受激发发出荧光的现象。在医学上，有运用电射引发人体内的自体荧光，用以以诊断癌症等疾病的方式。

Autofluorescence is the natural emission of light by biological structures such as mitochondria and lysosomes when they have absorbed light, and is used to distinguish the light originating from artificially added fluorescent markers (fluorophores).

The most commonly observed autofluorescencing molecules are NADPH and flavins; the extracellular matrix can also contribute to autofluorescence because of the intrinsic properties of collagen and elastin.