ELAEXIA® - Elective Labelling of Exosomes for Identification and Analysis
Currently applied methods for exosome purification are ultracentrifugation, precipitation using PEG, immunocapture with antibodies against CD9, CD63, CD81, TSG, Rab5, HLA-ABC, the use of microfluidic isolation, filtration, and size exclusion chromatography. However, methods such as filtration, size exclusion chromatography and precipitation lead to the isolation of a mixture of microvesicles, lipoproteins and exosomes and also bear the risk of damaging or destroying exosomes. The use of antibodies to CD9, CD81 and CD63 for immunocapturing and purification of exosomes will yield subpopulations of exosomes because oft he heterogenous loading of protein cargo into exosomes depending on the state of the cell. There is a lack of a standardised and reliable detection of exosome hampers (cross)validation of methods that are required to validate diagnostic workflows. To solve this problem, an identification and detection method is required, which is based on a ubiquitously present characteristic/element for all exosomes independent of their origin and protein cargo.
We developed ELAEXIA® as a diagnostic tool that binds specifically to the exosome lipid bilayer membrane, thus identifying all exosomes. Exosome biogenesis occurs inside multi-vesicular bodies, where the donor membrane for the budding exosome undergoes inward budding. This process leads to lipids located in the inner leaflet of membranes in cells, such as phosphatidylethanolamine (PE) or phosphatidylserine (PS) lipids such as phosphatidylserine (PS), being exposed on the outer leaflet of the exosome membrane (see Figure).
ELAEXIA® is a technology using a biopeptide binding with high specificity and affinity to phosphatidylethanolamine (PE) present on the outer leaflet of exosome membranes.
ELAEXIA® technology combines high specificity for exosomes with high sensitivity allowing thorough standardization of exosome-based workflows.
therawis diagnostics develops and delivers to themarket life science products based on this proprietary exosome platform as prime liquid biopsy diagnostics in oncology, virology and immunology enabling easier biomarker discovery and diagnostic performance through its unprecedented specificity and sensitivity.
