Publications by authors named "Tsuneo Okuyama"

Infectious virus purification techniques are important for vaccine development and gene therapy applications. However, the standardized one-step purification technique using ceramic hydroxyapatite (CHAp) has proven unsuitable for poliovirus. Therefore, we designed a sequential two-step chromatographic technique for purification of the infectious Sabin type 2 vaccine strain of poliovirus from the cell culture supernatant.

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Analysis of monoclonal antibody (MAb) heterogeneity caused by posttranslational modifications is important for pharmaceutical quality assurance of antibody drugs. In this study, by employing small ceramic hydroxyapatite (HAp) particles that were self-manufactured to have a 2.5-µm diameter, we attempted to separate and analyze MAb isomers.

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Although ceramic hydroxyapatite (HAp) chromatography has been used as an alternative method ultracentrifugation for the production of vaccines, the mechanism of virus separation is still obscure. In order to begin to understand the mechanisms of virus separation, HAp surfaces were observed by scanning electron microscopy after chromatography with dengue viruses. When these processes were performed without elution and with a 10-207 mM sodium phosphate buffer gradient elution, dengue viruses that were adsorbed to HAp were disproportionately located in the columns.

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Antibody purification using proteins A and G has been a standard method for research and industrial processes. The conventional method, however, includes a three-step process, including buffer exchange, before chromatography. In addition, proteins A and G require low pH elution, which causes antibody aggregation and inactivates the antibody's immunity.

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Polyethylenimine (PEI) has been widely used as a coating material to produce stationary phase for ion-exchange chromatography of biomolecules. However, a precise study of the PEI coating fraction has been lacking, despite such quantification being very important for fundamental research as well as identifying further industrial applications. In this study, we produced four types of PEI-coated hydroxyapatite (PEI-HAp) with various fractions of PEI (0.

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We have developed a new time-resolved fluorometric (TRF) microarray detection system consisting of fluorescent NH2 nanosphere, TRF microarray detector and gamma-irradiated polystyrene chip. Using the TRF microarray detector, we detected 500 particles of the fluorescent nanosphere in one channel. Cross-talk fluorescence from the adjacent channels was little observed in the TRF microarray detector (<0.

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Genetic testings are commonly employed in various fields of clinical medicine and the test items performed at clinical laboratories are increasing rapidly in number. They are utilized to make early and/or definite diagnoses of infectious diseases, leukemia, cancers and molecular inherited diseases and also to monitor the progress of the diseases. However, these genetic testings except for infectious diseases have been developed independently at each clinical laboratory and the test results obtained at each laboratory are not always compatible each other.

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