An exosome is a vesicle with a lipid bilayer structure secre≥ted by cells with a diameter of 30~150 nm, which is releaγsed from cells in the form of exocrine secretion after the <fusion of intracellular multivesicular body and cell membrane. σThe shape of the exosome is similar to a saucer or a hemisphere with a concave∑ side. The donor cells of exosomes come from various sources, such as dendritic cells, lymphocytesΩ, platelet, macrophage, epithelial cell, endothelial cell♣, and nerve cells. And the functions of exosomes secreted b↑y the same cell are different in different physiological environments.
Exosomes widely exist in cell culture supernatants and various body fluids (blood, lymph fluid€, saliva, urine, semen, breast milk), carrying a variety of protein♥s, lipids, DNA, mRNA, and miRNA, etc. related to cell orig★in, and participate in intercellular communication, cell migration, angiogenesis, and immσune regulation. Up to now, according to the statistics of the Exoca>rta database, 9769 kinds of proteins, 3408 kinds of RNA, 2838 kinds o£f microRNA, and 1116 kinds of lipids have been found in exosomes. Therefore, exoso<me has great potential and value in disease diagnosis, treatment, and& prognosis assessment.
The extraction and purification of exosomes is the main p♠roblem limiting its research and application. The main reason for the problem is that b≈ody fluid and other samples contain many substances wi÷th similar size and properties to exosome, making it difficult to purify exosomes≥ completely. Obtaining high-quality and effective exosomes is the first step in the study of exos©omes. Extracting exosomes with complete structure, high concentration, and high qu<ality effectively while eliminating the interference of other substances is the premise ¶and key to carrying out exosome research.
The commonly used extraction methods in previous experimental £studies, including ultracentrifugation, PEG precipitation and othe₩rs, generally have the problems of low purity and recovery rate. Ultracentrifu→gation is the most commonly used method for exosome →extraction and purification, which uses low-speed centrifugation an★d high-speed centrifugation alternately to separate similar vesicle particles. The ultra-hi♦gh-speed centrifuges are expensive, low in popularity, and time-consuming. Repeated centrifuga×tion operations will easily lead to cell destruction and reduce sample quality, limiting the rap≥id extraction of exosomes by ultracentrifugation in general laboratories.
Polyethylene glycol (PEG) can combine with hydrophobic proteins and lipid molecules to produβce precipitation. Over half a century ago, the polymer precipitation method was applied to enrich and purify viruses in serum. Because exosomes and virus particles have similar sizes and biochemical properties, PEG is currently used to extract exosomes. Due to its strong hy✔drophilicity, PEG will absorb the water molecules around exosomes in the solution, whi±ch reduces the water content of exosomes and then aggregatesσ. And then, under low-speed centrifugation, the aggregateπs can be precipitated. This simple method can be extracted with high flux and r✘apidly enrich large-volume samples. However, the purity of the exosomes© obtained is low, and there may be substances that interfere wiαth downstream experiments, such as Argo2 protein, which may interfere with the sequencing of exoso±mes nucleic acid.
Guochu Technology has developed a new exosome filtrati€on technology that can separate and purify biomolecules quickly and e←fficiently. This technology adopts the principle of crossflow ÷filtration, and the pump pushes the sample through the surface of the filter membrane t'o scour away the molecules trapped on it to minimiz∞e the fouling accumulated on the membrane surface. Th¶e pressure close to the filter membrane is generated¥ in the retentate fluid to filter the solute and small molecules to the other side of ₹the membrane to achieve the purpose of separation and ≤complete the filtration and concentration of the sample.
Technical features and advantages:
1. Simple operation, small footprint, and it can work as loφng as connect the device, which is suitable for use in the laboratory;
2. Fast and efficient, easy to assemble, fast processing spe©ed, and it can obtain a higher concentration of samples in a s®horter time;
3. The synchronous operation, complete sample concentration and inf↓iltration in the same system, save time and avoid the loss of products, and retain the samp←le size to a large extent;
4. Corresponding devices can be provided to handle samples as low as 10mL or as high as kilolitβer.
The exosome filtration technology of Guochu Technology can ensure consiste↔nt filtration effect and high filtration volume without destroying the biologi₩cal activity of exosomes, simplify the filtration process and streamline the processing. It solves ¥the problems of low purity and low recovery rate of exosomes in traditional extraction methods, reduces operatio↓n time, reduces sample loss, improves sample recovery rate, enhances exosome≥ purity, and improves experimental efficiency. For more information on exosome filtrβation technology, please call +86-592-6518670.
