Quantitative analysis of autophagy-related protein LC3B by quantum-dot-based molecular imaging

Autophagy is a process that facilitates the maintenance of intracellular homeostasis by removing unnecessary or dysfunctional cellular components. It plays a role in inhibiting tumorigenesis in the early stage of the disease and might promote progression after tumor formation. Microtubule-associated protein light chain 3 (MAPLC3, better known as LC3), isoform B (LC3B), is one of the most commonly used markers of autophagy. The expression of LC3B has been studied in many cancers and was shown to be closely related to tumor progression. Here, we provide detailed experimental steps for the quantitative detection of LC3B expression in cancer tissue by quantum-dot-based molecular imaging. As compared to the traditional immunohistochemistry (IHC) employing standard fluorochromes, the present method has a higher signal amplitude and improved sensitivity enabling the accurate quantitative detection, which provides a foundation for functional research and the clinical application of LC3B biomarker.