Service no. | Service scope | Service description | Reference fee | Turnaround |
1 | Protein quantification (BCA) | Measure EV-preparation protein concentration by BCA assay. | 50 CNY/sample | 1 business days |
2 | Protein-marker testing (Western blot) | Assess EV-associated protein markers by Western blot. | 100CNY/sample/marker | 3 business days |
3 | Protein analysis（NanoFCM) | Assess EV-associated protein markers by nano-flow cytometry. | 200 CNY/sample/marker | 3 business days |
4 | Protein analysis（WES) | Assess EV-associated protein markers by automated capillary immunoassay (WES). | 300CNY/sample/marker | 3 business days |
EVs contain proteins that can provide information about their origin, function and characterization. Common methods include Western blot, ELISA, LC-MS/MS and nano-flow cytometry (NanoFCM). The source describes a MISEV 2018-based combination of transmembrane, cytosolic and negative protein markers (three positive and one negative), with the choice adapted to sample quantity, species-specific antibodies and instrument limitations.
1. Western blot
Western blot detects EV marker proteins through specific antigen–antibody binding. The source lists five positive-marker antibodies (CD9, CD63, CD81, TSG101 and Syntenin) and one negative-marker antibody (Calnexin) available for selection. Because EV immunophenotypes vary, some positive markers may fall below the Western blot detection limit. The described workflow includes a positive control; the source also suggests considering more sensitive methods such as the Flow NanoAnalyzer or WES system.
2. Nano-flow cytometry (NanoFCM)
EV surface proteins can be assessed by incubating vesicles with fluorescently labelled specific monoclonal antibodies and measuring the proportion of positive particles by nano-flow cytometry. The source lists CD9, CD63 and CD81 as common markers and describes removing excess unbound antibody by ultracentrifugation before measurement. It states that the three standard antibodies cover human and mouse proteins; customers must provide directly labelled antibodies for other species or surface markers.
3. Automated protein quantification (WES)
The source describes the Wes Simple Western system as combining sample separation, capture, immobilization, immunodetection and quantification in one sample tube without gel casting, electrophoresis gels or membrane transfer. It reports automated antibody incubation, chemiluminescent detection and analysis; a 3–5 μL sample volume; an approximately three-hour run; sensitivity down to the picogram level; and results including target protein size, signal-to-noise ratio, peak area and content.
Lifeint provides EV research and application services from sample preparation, isolation and characterization to omics, functional studies, modification and scale-up. It jointly established a biomedical technology centre with Xiamen University School of Pharmaceutical Sciences, built process-development laboratories to GMP standards, and contributed to an EV expert consensus. Its service records cover more than 300 plant species.
Scan to contact us on WeCom
