The process is based on the binding between CB and AdA. CB is bound to the fluorescent dye Cy3 (colored in green) and enters the lysosomes, while AdA is bound to the fluorescent Cy5 (colored in red) which accumulates in mitochondria. In the autophagy process, the two cellular organelles fuse together, leading to the encounter of CB and AdA. The scientists can detect the fusion, because when the two fluorescent dyes move closer, they interact with each other via the fluorescence resonance energy transfer (FRET) mechanism. In this way, the research team can analyze the autophagy process step by step.