Fig. 3
![Fig. 3](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs12964-024-01548-3/MediaObjects/12964_2024_1548_Fig3_HTML.png)
Strategies for the labelling of endogenously produced EVs for the study of their functional transfer. A Cre-LoxP method. B CRISPR-Cas9 method. C Principle of Cre-LoxP system: Cre-mediated recombination activates a fluorescence switch from DsRed to eGFP in reporter+ cells after receiving Cre+-EVs produced by Cre+ cells. D Mechanism of CRISPR-Cas9: Reporter+ cells expressing Cas9 switch from mCherry to eGFP fluorescence after functional uptake of EVs. EVs produced by genetically manipulated donor cells carry a specific targeting single guide RNA (sgRNA) that navigates Cas9 with nuclease activity to generate cleavage of the target sequence