Exosomes were originally described to be released from sheep reticulocytes. With the large number of studies that followed, exosomes were found to exist in almost all body fluids, primarily blood, urine, cerebrospinal fluid, saliva, pleural effusion, ascites fluid,9 amniotic fluid, breast milk, and bronchoalveolar lavage fluid (BALF). Originated from the endosomal pathway via the formation of late endosomes or multivesicular bodies, exosomes enclose a variable spectrum of molecules characterized by parent cells, including nucleic acids (DNA, mRNA, microRNA (miRNA), lncRNA, circRNA, etc.), proteins, and lipids, which can be transported over distances via circulating system within the protection of a lipid bilayer-enclosed structure.

As an important biological component of liquid biopsy, exosomes have several advantages compared to tumor‐educated platelets(TEPs), circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA). It attracted the greatest interest in exosome research as a biomarker carrier for diagnosis over the past 10 years, especially in 2018. Based on a PubMed search in January 2020, publications regarding the diagnostic efficacy of exosomes in the past 5 years with the MeSh Terms “exosomes” OR “small extracellular vesicles”, “diagnosis” OR “biomarker”, and “liquid biopsy”, there were 88 relevant publications on DNA, 695 on RNA (including 74 about mRNA, 534 about microRNA, 52 about lncRNA, 14 about circRNA), and 824 on protein. Protein is the most-studied content of exosomes, followed by miRNA. 

Purification and isolation processes for exosomes are critical when using or exploring the exosomes as diagnostic biomarkers. Different laboratory-based isolation protocols are available, such as differential ultracentrifugation, size-exclusion chromatography, immunoaffinity-based capture, polymer precipitation, polymer precipitation, microfluidic-based isolation, and commercially available kits that scientists use to yield exosomes. Polymer precipitation is the most simple, high-throughput, and fast method. in spite of the impurity of isolated with protein or polymer contaminants, exosomes isolated via polymer precipitation work well for nucleic acid based assay and immuno assay, such as western blot etc. TOOLS provides high-quality exosome precipitation reagents with modified formulation according to the complexity of sample:

 

To see more, click TOOLS Life Science Reagents - tools-biotech.com‎

Exosome characterization is very challenging due to the heterogeneity of the exosome population. According to Minimal information for studies of extracellular vesicles 2018 (MISEV2018), exosome characterization by multiple, complementary techniques is important to assess separation methods and to establish the likelihood that biomarkers or functions. General methods used for particle size is nanoparticle tracking analysis (NTA) which utilizes Brownian movement of the exosomes to determine the size and particle concentration. TOOLS provides NTA service with the industry-leading NanoSight3000 of Malvern Panalytical. NanoSight NTA system supports work within ISO19430: 2016 Particle Tracking Analysis (PTA) Method and ASTM E2834-12 (2012) Standard Guide for Measurement of Particle Size Distribution of Nanomaterials in Suspension by NTA.

Newly developed techniques possibly reveals multiparameter analysis of exosome, TOOLS provided the advanced Nano Flow cytometry service. In addition to exosome size and concentration, and Nano Flow cytometry could combines a fluorescence system with immunofluorescence staining to analyze the surface proteins of exosomes, providing chemical and biological characteristics of exosomes, and correlated analysis of these attributes can be facilitated at the single-nanoparticle level.. The effective analysis range is 7-1000 nm particles, so the application is limited to exosomes, but also for defining lipidnanoparticles (LNP) and encapsulation rates, and for analyzing viral particles. It can be used to define lipidnanoparticle (LNP) and encapsulation rate, as well as to analyze viral particles. Our service utilizes NanoFCM FLOW NANOANALYZER, which has been adopted by many well-known national research institutes and pharmaceutical industry leaders, such as the National Institutes of Health, Lonza, MD Anderson Cancer center, evotec, etc., to bring research into line with international standards.

Then for morphology characterization, available techniques are scanning electron microscopy (SEM) and transmission electron microscopy (TEM).

Mass spectrometry and miRNA assay are then further used to reveal insight biological characterization and information about disease. In particular, two-dimensional gel electrophoresis (2DGE) and liquid chromatography coupled tandem mass spectroscopy (LC-MS) are predominantly used. TOOLS provides mass-spectrometry-based proteomics. Our technical department has more than 10 years of experience in operating mass spectrometry and handling various types of samples, and are experienced in processing exosome. Beside extracting and identifying the total protein from exosomes, our service team also provide exosome shaving process which only extracts and allows particularly analysis of the exosome surface proteins. Then the sample undergo qualitative (understanding proteins in composition) and quantitative analysis, as well as we provide a wide range of bioinformatics services to reveal important biological information from exosomes.
 

 

To see more and inquired about our MS proteomics service, click: https://www.tools-biotech.com/service/index/cid/72.html

Exosome miRNAs (ex-miRNAs) are highly stable and resistant to degradation. Therefore, these may serve as useful biomarkers for the early clinical diagnosis for cancer, infection,metabolic disorders, Neurodegenerative Diseases etc . For the stage of investigating disease significantly related miRNA target, TOOLS miRNA RT-qPCR Assay System provide accurate and satisfactory results. The core of TOOLS miRNA RT-qPCR Assay System is the unique designed stem-loop RT primer for mature miRNAs, followed by the compatible qPCR primers and a miRNA-specific TaqMan florence probe is employed for highly specific recognition on target mature miRNA. There are pre-designed and validated primer/probe sets over 200 human mature miRNA targets available, 100 for mouse, and 80 for rat. Custom design for your miRNA target is also available. It is easy to use, and allows rapid, sensitive, and specific profiling the expression of microRNA (miRNA) within the simple 2-step RT-qPCR procedure. Review the whole list and explore how to use the TOOLS miRNA RT-qPCR Assay System, click https://www.tools-biotech.com/product/index/cid/176.html

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