Flavin adenine dinucleotide (FAD) autofluorescence from cells reports on the enzymatic activity which involves FAD as a cofactor. Most of the cellular FAD fluorescence comes from complex II of the electron transport chain in mitochondria and can be assessed with inhibitor analysis. The intensity of FAD autofluorescence is not homogeneous and vary between cells in tissue and in cell culture types. Using primary co-culture of neurons and astrocytes, and human skin fibroblasts we have found that very high FAD autofluorescence is a result of an overactivation of the mitochondrial complex II from ETC and from the activity of monoamine oxidases. Cells with high FAD autofluorescence were mostly intact and were not co-labelled with indicators for necrosis or apoptosis. However, cells with high FAD fluorescence showed activation of apoptosis and necrosis within 24 h after initial measurements. Thus, high level of FAD autofluorescence is an indicator of cell pathology and reveals an upcoming apoptosis and necrosis.

细胞的黄素腺嘌呤二核苷酸 (FAD)自发荧光报告了涉及 FAD 作为辅因子的酶活性。大多数细胞 FAD 荧光来自线粒体电子传递链复合体 II ，可以通过抑制剂分析进行评估。FAD 自发荧光的强度并不均匀，并且在组织和细胞培养类型的细胞之间存在差异。使用神经元和星形胶质细胞以及人皮肤成纤维细胞的原代共培养，我们发现非常高的 FAD 自发荧光是 ETC 和单胺氧化酶活性导致线粒体复合物 II 过度激活的结果。具有高 FAD 自发荧光的细胞大多是完整的，并且没有与坏死或凋亡指示剂共同标记。然而，具有高 FAD 荧光的细胞在初始测量后 24 小时内显示出凋亡和坏死的激活。因此，高水平的 FAD 自发荧光是细胞病理学的指标，并揭示即将发生的细胞凋亡和坏死。