CMV-CD9-mCherry-FLAG Lentivirus

The CMV-CD9-mCherry-FLAG lentiviral vector combines a strong constitutive CMV promoter with a CD9-mCherry-FLAG fusion expression cassette, enabling stable and long-term expression in various mammalian cells. As a lentiviral delivery system, it offers highly efficient transduction, effectively transducing even difficult-to-transfect cell types, and supports sustained expression, making it suitable for generating stable cell lines and conducting long-term studies. CD9 is a tetraspanin protein enriched in the plasma membrane and extracellular vesicles, providing membrane localization and marking CD9-positive compartments, while the mCherry fluorescent protein emits bright red fluorescence for real-time visualization with minimal spectral overlap with green fluorescent proteins. The small FLAG epitope tag facilitates various antibody-based detection methods, suchs as Western blotting, immunocytochemistry, and affinity enrichment, providing users with an orthogonal detection method complementary to fluorescence imaging. The dual labeling capabilities with both a fluorescent tag and an epitope tag enable cross-validation of detection at both the protein and vesicle levels, thereby increasing data reliability.

This lentiviral tool is ideal for applications in extracellular vesicle biology, membrane trafficking, and live-cell imaging, where continuous labeling and strong signals are crucial. Researchers can visualize CD9-positive structures to monitor vesicle biogenesis, membrane organization, and trafficking pathways, and use fluorescence detection methods to track the release and uptake of CD9-enriched extracellular vesicles in donor-recipient cell systems. The FLAG tag supports immunoprecipitation of CD9 complexes to analyze interacting protein partners or enrich CD9-carrying vesicles for proteomic characterization, enabling the integration of imaging and biochemical methods within the same model system. In screening and drug discovery, this platform can be used to compare how genetic perturbations or test compounds affect CD9 distribution, extracellular vesicle abundance, or vesicle cargo profiles, providing a sensitive cell-based assay for vesicle pathway modulators.