Exosomes are small vesicles secreted by cells with a diameter of 30-150 nm. They contain proteins, mRNA, microRNA and other molecules. Exosomes can circulate in various body fluids and reach other cells and tissues, where they regulate physiological and pathological processes. The surface of exosomes contains tetraspanins, integrins and other proteins. Tetraspanins, such as CD9, CD81, CD63, are common markers that can be used for exosome identification and detection
The ExoHiLA™ exosome assay is a bead-based, no-wash luminescent assay for the detection of exosome particles. The assay is based on two nanobeads (donor beads and acceptor beads), and the beads are coated with antibodies that recognize specific proteins on the exosome surface. When Donor and Acceptor beads are brought together through binding to the exosome target (such as CD9, CD81, CD63), a cascade of chemical reactions is set in motion, creating an amplified signal.