AIM:To develop a novel method for the rapid and efficient extraction of exosomes secreted by tumor cells.METHODS:Unlike the traditional extraction method,the supernatants of cell cultures were concentrated,and the exosomes were isolated promptly and effectively using a novel nanomaterial called ExoQuick.Coomassie brilliant blue staining was used for protein quantification,and the morphology of the exosomes extracted by both methods was visualized by transmis-sion electron microscopy.Exosome marker proteins were detected by Western blot analysis.Two potential hepatoma-associated proteins,tissue transglutaminase2(TGM2)and annexin A2,were analyzed.RESULTS:The exosomes separated by the new extraction assay based on the nanomaterial were discshaped,intact vesicles with lipid bilayer membranes.They were approximately 30-100 nm in diameter,which is similar to the diameter of exosomes isolated by the traditional method.The protein concentration of exosomes extracted by the new method was approximately780μg/108 cells,and therefore,it was 19 times higher than that of exosomes extracted in the traditional manner.There were differences between the total proteins of Huh-7 cells and the exosomal proteins.Typical exosome proteins,such as the transmembrane protein CD63 and heat shock protein 70,were confirmed.Two potential hepatoma-associated proteins were also identified.TGM2 was first found to exist in the exosomes of human liver cancer cells,but annexin A2 was not secreted into exosomes.CONCLUSION:The new extraction method based on the nanomaterial is quick and efficient.The cancerassociated protein TGM2 can be secreted through an exosome-mediated non-classical secretion pathway,and it may be a valuable tumor marker. AIM: To develop a novel method for the rapid and efficient extraction of exosomes secreted by tumor cells. METHODS: Unlike the traditional extraction method, the supernatants of cell cultures were concentrated, and the exosomes were isolated promptly and effectively using a novel nanomaterial called ExoQuick . Comassie brilliant blue staining was used for protein quantification, and the morphology of the exosomes extracted by both methods was visualized by transmis-sion electron microscopy. Exosome marker proteins were detected by Western blot analysis. Two potential hepatoma-associated proteins, tissue transglutaminase 2 ( TGM2) and annexin A2, were analyzed .RESULTS: The exosomes separated by the new extraction assay based on the nanomaterial were discshaped, intact vesicles with lipid bilayer membranes. They were approximately 30-100 nm in diameter, which is similar to the diameter of exosomes isolated by the traditional method.The protein concentration of exosomes extracted by the new method was appro ximately780 μg / 108 cells, and therefore, it was 19 times higher than that of exosomes extracted in the traditional manner. There were differences between the total proteins of Huh-7 cells and the exosomal proteins.Typical exosome proteins, such as the transmembrane protein CD63 and heat shock protein 70, were confirmed. Two potential hepatoma-associated proteins were also identified. GM2 was first found to exist in the exosomes of human liver cancer cells, but annexin A2 was not secreted into exosomes. CONCLUSION: The new extraction method based on the nanomaterial is quick and efficient. The cancerassociated protein TGM2 can be secreted through an exosome-mediated non-classical secretion pathway, and it may be a valuable tumor marker.