• The Journal of the Korean Society for Microbiology
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• v.22 no.4
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• pp.377-392
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• 1987

Monoclonal antibody to the Escherichia coli heat-stable enterotoxin(ST) was produced to develop a rapid and convenient diagnostic method to the ST. The toxin was purified from culture supernatant of enterotoxigenic E. coli O148H28($ST^+/LT^+$) and conjugated to bovine serum albumin(BSA). The ST-BSA conjugate was used to immunize BALB/c mice and the immune spleen cells from these mice were fused with $P3{\times}63$ Ag8.V653 plasmacytoma cells. Hybridomas were screened by ELISA and positive hybridomas were cloned by limiting dilution. Finally, one stable clone (AS36) specific to ST was selected for further growth and characterization. Antibody titers of culture supernatant and ascitic fluid from BALB/c mice were 1:1,024 and 1:20,480 respectively in ELISA. The isotype and subclass of monoclonal antibody was IgG1 in sandwich ELISA. To test the neutralizing effect of monoclonal antibody on toxin activity of ST, mixture of ascitic fluid and ST was assayed by infant mouse assay and this monoclonel antibody was proved to be a neutralizing antibody. The titer of ascitic fluid which completely neutralized biological activity of 4 units of ST was 1:4. Purified ST was quantitatively measured by competitive ELISA and minimum amount of ST detectable by this assay was 250pg, which was an amount six-fold smaller than that detectable by infant mouse assay. Four reference strains of enterotoxigenic E. coli from WHO were detected by competitive ELISA and highly specific, sensitive and reproducible result was obtained.

• The Journal of the Korean Society for Microbiology
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• v.22 no.3
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• pp.197-208
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• 1987

Chlamydia trachomatis has now shown that this interesting intracellular parasite is a cause of nongonococcal urethritis, infantile pneumonia, pelvic inflammatory disease and epididymitis, in addition to lymphogranuloma venerum and inclusion conjunctivitis. There are several diagnostic methods for C. trachomatis, but the method using monoclonal antibody is the most sensitive and specific. The hybride cell were prepared by fusion of myeloma cell($P_3X_{63}\;Ag_8{\cdot}V_{653}$) of mouse and lymphocyte of mouse(BALB/c) that were immunized with formalin killed C. trachomatis serotype D. The cell mixtures after fusion were dispensed into 640 wells of the 96 well culture plates and continuously cultured in HAT medium for 2 weeks. The supernatants of culture media in 83(13%) wells were reacted with C. trachomatis, which were determined by enzyme-linked immunosorbent assay in 96 well microplate. The clones that secreted antibody to C. trachomatis were cloned by limiting dilution. Only six monoclones secreted antibody to C. trachomatis. The antibody titer of ascitic fluid that collected from same BALB/c mice bearing hybridoma cells was above 1:100,000. These monoclonal antibodies that were IgG reacted with elementary and reticulate bodies of all serotypes(Ba, D, E, F, G, H, J and LGV type-I) using ELISA and indirect immunofluorescence stain, but there were no cross reaction with other bacteria(coagulase negative Staphylococcus, Proteus and E. coli). We concluded these six monoclones secreted the same monoclonal antibody to C. trachomatis. The sensitivity and specificity of the monoclonal antibody compared with Microtrak(confirmatory test of C. trachomatis, Syva) was 100%, respectively.

• Journal of Life Science
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• v.8 no.5
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• pp.571-575
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• 1998

The nerve system specific protein of Drosophila melanogaster was produced by using heads of flies as the antigen. The monoclonal antibody 6H6 recognized the disabled molecules that a kind of tyrosine kinase substrate by expres-sion cDNA library screening method. At the same time, the antibody also specifically recognized C-terminal region of disabled protein from 7427 to 8761bp by DNA sequencing. In early embryos, the localization of antigen appeared in the central nerve system. In adult flies, the antigen showed specific localization on the axon of optic nerve, cerebral nerve and thoracic nerve, and they also expressed on the muscular nerve. The molecules of disabled are expected to carry an important function in developing central nerve system. In adult flies, it is suggested that the disabled molecules have a role for muscular nerve as well as neural axon.

• Microbiology and Biotechnology Letters
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• v.16 no.5
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• pp.335-342
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• 1988

An anion exchange chromatography was employed for the purification of mouse monoclonal antibodies from ascitic fluid and in vitro cultivation media. After cultivation of hybridomas, Alps 25-3, HCGK, A4W, and KW, producing IgG1, the culture supernatants were harvested by centrifugation, precipitated with 50-60％ ammonium sulfate, and dialyzed against 0.025 M Tris-HCI buffer (pH 8.2). Then the dialyzed samples were loaded into a DEAE-Trisacryl M anion exchange column. Monoclonal antibodies bound to the DEAE-Trisacryl M were eluted with 0.025 M Tris-HCI buffer (pH 8.2) containing 30-40 mM NaCl. In ammonium sulfate precipitation, the recovery of the monoclonal antibody was shown to be 90％ and 84％ from in vitro culture media containing 10％ and 2％ fetal bovine serum, respectively. On the other hand, the pretreatment by ultrafiltration enhanced the yield up to 91％ whereas the purity was lower than that by ammonium sulfate treatment. Subsequently, in the DEAE-Trisacryl M chromatographic separation, the purities and recoveries of all the monoclonal antibodies from both the in vitro culture supernatants and ascitic fluids were 70-80％ and 65％ respectively. The monoclonal antibody, Alps 25-3 could be further purified with a purity of 95％ through an immunoadsorbent chromatography.

• Korean Journal of Microbiology
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• v.28 no.1
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• pp.6-12
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• 1990

The preS2 wequence of an adr hepatitis B virus was cloned and expressed in Escherichia coli as a $\beta$-galactosidase fusion polypeptide. Recombinant preS2 product interacted with the preS2-specific monoclonal antibody H8 which was induced by surface antigen particles isolated from a Korean gepatitis patient. The H8 showed only a minor cross-reactivity with recombinant preS2 product of adw2 subtype. Determination of nucleotide sequence of the adr preS2 revealed that twelve amino acid residue substitutions between adr and adw2 subtype sequences. The antigenic determinant to H8 must include some of these differences.

• Korean Journal of Veterinary Research
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• v.38 no.2
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• pp.336-344
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• 1998

Eight monoclonal antibodies(MAbs) against the transmissible gastroenteritis virus (TGEV) were produced and characterized. Four of the MAbs were produced against a reference TGEV, Purdue strain(P115) and the others were produced against the Korean vaccine virus, Pyungtaek strain. Only one MAb(5C8) produced against P115 had neutralizing activity and was found to be E2 protein-specific. The other seven MAbs(4E2, 4G8, 5H6, 1F8, 2C6, 5H5, and 3A6) had specificity of nucleocapsid protein and no neutralizing activity. All MAbs reacted with different strains of TGEV, but none of the MAbs was reactive with porcine enteropathogenic viruses such as rotavirus, epidemic diarrhea virus and enterovirus by fluorescence antibody(FA) test.

• KSBB Journal
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• v.10 no.3
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• pp.323-334
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• 1995

The effects of glucose on cell growth kinetics, monoclonal antibody productivity, and cell metabolism or hybridoma cells were investigated. The mouse-mouse hybridoma cell line VIII H-8 producing mouse IgG2a was used as a modal system. Glucose showed substrate inhibition type dependence on specific growth raie. The maximum cell density increased as initial glucose concentration increased up to 4 g/$\ell$. Glucose showed a strong influence on cell death kinetics, and an inverse relationship between specific death rate and glucose concentration was found. Cell viability and monoclonal antibody production increased as initial glucose concentration increased. The specific glucose consumption rate increased with glucose concentration, and cumulative specific lactate production rate increased with increasing initial glucose concentration. The overall kinetics of ammonium ion production was almost invariant with respect to initial glucose concentration, while the cumulative specific ammonium ion production rate was dependent on initial glucose concentration.

• The Korean Journal of Zoology
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• v.34 no.1
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• pp.44-53
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• 1991

Distribution of the antigens during the cell cycle of amoebae was followed by immunof-luorescence microscopy using a monoclonal antibody against the nucleus as a probe. While the cells were in the interphase, the antigen was localized on the nucleus membrane. But it was dispersed all over the cytoplasm during mitosis and cytokinesis. The molecular weights of the immunoreacted antigens were 210 KD and 190 KD as determined by SDS PAGE and western blotting of the purified nuclei. The antigens were not soluble in non-ionic detergent, but were released from the nucleus by incubation with 0.05 M sodium carbonate, pH 10.6 or with 8 M urea at serial chemical extraction. Thus the antigens appeared to be peripheral proteins of the nurBeus envelope. The isoelectic point of both antigens was 7.64 as determined by 2 D PAGE and transfer blotting. Considering the peiipherd association with the nucleus membrane and the dispersed distribution during mitosis, the antigens could be lamin like proteins. Hourever, it appears also possible that they are the component molecules of the unusually structured aurous lamina of amoeba nucleus since they have the large molecular weight and the basic pl.

• The Korean Journal of Zoology
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• v.35 no.1
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• pp.1-7
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• 1992

Seven monoclonal antibodies were produced by fusing splenocytes from Balb/C mouse immunized with partially purified human interferon-a (HUIFN-a) with NSO plasmacytoma cells. aery were identified as five IgG class (432.22: IgG2b/n, 460.52: IgG2b/a , 548.46: IgG2a/n , 573.10: IgG2b/h , 625.12: IgG2b/n ), one IgA class (460.50: IgA/n ) and one IsM class (465.27: IgA/n ), and all of them revealed highly sensitive to HUIFN- a IgG class monoclonal antibodies have pts ranged from 8.2 to 8.6. Ascites fluids produced from primed Balb/c mice and were purified through column chromatography. The cytopathic effect (CPE) inhibition assay to examine neutralization of HuIFU-a by IgG class monoclonal antibodies, gave that MAbs 460.52, 548.46, 573.10 can neutralize HUIFU- a arith varying degrees except 432.22. Therefore, it is deduced that these various monoclonal antibodies may recognize the distinct epitopes on HUIFN-a.

• Applied Chemistry for Engineering
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• v.30 no.4
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• pp.429-434
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• 2019

A lateral flow immunoassay platform utilizing antibody functionalized water soluble CdSe/ZnS semiconductor quantum dots (QDs) was developed for the analysis of human serum amyloid A-1 (hSAA1) in a buffer solution. hSAA1 was chosen as a target protein because it is regarded as a potential biomarker associated with early diagnosis and prognosis in patients of lung cancer. The immunoassay strip on a nitrocellulose membrane was fabricated by spraying two lines composed of a test line with a monoclonal antibody against hSAA1 (10G1) (anti hSAA1) and a control line of anti-chicken IgY. While the CdSe/ZnS QDs synthesized in an organic phase were transferred to a water phase by ligand exchange using carboxylic acid modified alkane thiol. The QDs was then conjugated to monoclonal antibody against hSAA1 (14F8) [anti hSAA1 (14F8)] and used as a fluorescent detection probe. The sequential lateral flow of hSAA1 in different concentration and QDs-anti hSAA1 (14F8) complex allowed to form the surface sandwich complex of anti hSAA1 (10G1)/hSAA1/QD-anti hSAA1 (14F8), which was then analyzed using fluorescence microscope. A 100 nM concentration of hSAA1 protein can be detected by naked eyes under an optimized lateral flow buffer condition with a sensing time of 5 mins.