• Journal of Applied Biological Chemistry
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• v.48 no.1
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• pp.16-25
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• 2005

To develop an enzyme-linked immunosorbent assay (ELISA) for the detection of the residues of the acaricide fenazaquin, five haptens were synthesized and assessed. A competitive indirect format was used with polyclonal antibodies. Under an optimized condition using the selected rabbit C antiserum, an $IC_{50}$ of $96.97\;ng{\cdot}ml^{-1}$, the detection range of $14.9{\sim}631\;ng{\cdot}ml^{-1}$, and the lowest detection limit of $8\;ng{\cdot}ml^{-1}$ were obtained. Some structurally related compounds of practical use showed low crossreactivities to the antibody. Highest cross-reactivity observed with hapten IV indicates that the antiserum C recognizes very well quinazoline ring, 4-tert-butylphenyl, and an adequate length of spacer arm. The length of spacer arm affected recognition of quinazoline ring and 4-tert-butylphenyl moieties. When applied to apple and pear, recoveries were within acceptable ranges of $93.18{\sim}104.77%$ (n = 4) and $79.40{\sim}111.95%$ (n = 4), respectively.

• Bulletin of the Korean Chemical Society
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• v.26 no.6
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• pp.939-942
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• 2005

For the detection of cyanobacterial toxin, an Enzyme-linked immunosorbent assay (ELISA) was integrated into a PDMS microchip. The conjugates of microcystin-LR (MCLR) and keyhole limpet hemocyanin (KLH) were adsorbed on the surface of polystyrene beads and these MCLR-KLH polystyrene beads were introduced into a microchamber. MCLR on the surface of polystyrene beads reacted with horseradish peroxides (HRP) conjugated anti-MCLR monoclonal antibody (mAb) which had a competitive reaction with MCLR in water sample. After the enzyme substrate 3,3,5,5-tetramethyl benzidine (TMB) was injected into the chamber and catalyzed by HRP, the color change was detected with a liquid-cord waveguide. This integration shortened the conventional ELISA analysis time from several hours to about 30 min with only 4.2 $\mu$L MCLR sample consuming which was useful for the environmental analysis. More over, troublesome operations required for ELISA could be replaced by simple operations. The microchip based detection system showed a good sensitivity of 0.05 $\mu$g/L and maintained good reliability through its quantitative range with low coefficients of variation (2.5-10.5%).

• Bulletin of the Korean Chemical Society
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• v.23 no.8
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• pp.1116-1119
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• 2002

Monoclonal antibodies have been generated against a generic hapten, ο,ο-diethyl ο-(5-carboxy-2-fluorophenyl) phosphorothioate, for the determination of organophosphorus (OP) pesticides in a class-specific manner. In an indirect competitive enzyme-linked immunosorbent assay (ELISA) format, employing a heterologous coating antigen, these monoclonal antibodies showed desirable properties for use in the class-specific determination, i.e., broad specificity and high sensitivity. The IC50 values of four commonly used ο,ο-diethyl OP pesticides were fairly uniform ranging from 0.1 to 0.3 ㎛/mL. The IC50 values of three ο,ο-dimethyl derivatives were between 0.3 and 1.4 ㎛/mL. These values, together with the limits of detection (LOD), were better, in terms of the specificity and sensitivity, compared with the values obtained previously with polyclonal antibodies.

• Korean Journal of Veterinary Service
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• v.35 no.4
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• pp.269-273
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• 2012

A confirmatory serological test, the standard tube agglutination test (STAT) is evaluated for the diagnostic efficiency in brucellosis Korea. A total of 345 bovine samples were collected from regional veterinary branch under national brucellosis monitoring program from January 2010 to June 2012 in Korea. These samples were diagnosed as suspected serum and brucellosis positive by the Rose Bengal test (RBT) and the STAT, respectively. The STAT was compared and evaluated with three serological test such as the indirect-enzyme linked immunosorbent assay (I-ELISA), competitive-enzyme linked immunosorbent assay (C-ELISA) and fluorescence polarisation assay (FPA) prescribed for international trade by OIE. Among the 345 bovine serum samples, 302 (87.5%) were diagnosed as positive in the STAT, while 215 (62.3%), 223 (64.6%) and 194 (56.2%) serum samples were diagnosed as positive for brucellosis in the I-ELISA, C-ELISA and FPA, respectively. The STAT showed quite high positive results as compared with three prescribed tests of OIE. FPA, I-ELISA and C-ELISA have shown 60.6%, 64.9% and 67.2% correlation, respectively as compared to the STAT. However correlations of three prescribed tests ranged high 84.1~97.7%. Especially, correlation between I-ELISA and C-ELISA is quite high, 97.7%. These results suggest that the STAT has shown many false-positive reactions. Therefore, additional serological test, such as ELISAs and FPA, would be necessary to adopt as a confirmatory test in the national surveillance program of bovine brucellosis in Korea.

• Development and Reproduction
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• v.9 no.2
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• pp.135-142
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• 2005

Vitellogenins(VTGs) are the precursor of egg-yolk proteins in most oviparous species from invertebrates to vertebrates. In oviparose vertebrates, VTGs are synthesized in the liver and transported through the blood to oocytes. In female fish, concentrations of plasma VTG increase rapidly at onset of vitellogenesis in the normal reproductive cycle. Male fishes also possess the gene for VTG, but plasma concentrations of the protein typically remain small, presumably due to low levels of endogenous estrogens. However, exposure of males to exogenous estrogenic mimics can result elevated. Therefore, the VTG in fish can be used as a useful biomarker for appropriate tools of endocrine disrupting compounds effects. In this studies, we prepared the test methods that can measure the plasma VTG level in the gobies that live in polluted area with mimic estrogen. For the purpose, we purified VTG of floating goby(Chaenogobius annularis) and prepared specific monoclonal and polyclonal antisera to yolk protein, then developed a sandwich competitive ELISA system for measurement of plasma VTG levels. Validation for the ELISA system using monoclonal and polyclonal antibodies against VTG was tested. The absorbance curve of serial dilutions of serum from vitellogenic female was paralleled to the standard curve of VTG, but normal male was not paralleled. The developed sandwich ELISA system was measured for VTG levels in plasma of common goby(Acanthogobius flaviman) and javeline goby(A. hasta) as well as in plasma of floating goby(C. annularis).

• Korean Journal of Food Science and Technology
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• v.41 no.2
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• pp.215-219
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• 2009

To conduct a risk assessment of $AFB_1$ intake, $AFM_1$, which is a metabolite of $AFB_1$ in the human and porcine urine, was determined by competitive direct ELISA (cdELISA). The detection limit of cdELISA using anti-$AFM_1$ antibody and $AFB_1$-HRP conjugate was 10 pg/mL. The recoveries of $AFM_1$ were 117-167% after the addition of $AFM_1$ in the human urine in a range of 3-100 pg/mL. 165 samples (95.5%) of those obtained from 172 persons evidenced measurable levels of urinary $AFM_1$. The detected $AFM_1$ ranges were 0-11.6 pg/mL and the average level of $AFM_1$ contamination was 2.74${\pm}$ 1.89 pg/mL. The estimated amount of $AFM_1$ excretion in the human urine was 3.97 ng/day and the estimated $AFB_1$ intake amount was 79.4 ng/day. The probable daily intake (PDI) of $AFB_1$ by the subjects was estimated to be 1.28 ng/kg bw/day, which was higher than the tolerable daily intake (TDI, 0.15 ng/kg bw/day). In the case of porcine urine, the $AFM_1$ ranged between 0.97-26.7 pg/mL and the average contaminated $AFM_1$ was 10.62${\pm}$4.39 pg/mL. The estimated amount of $AFM_1$ excretion in the porcine urine was 27.6 ng/day, and the estimated $AFB_1$ intake amount was 551 ng/day.

• Journal of Food Hygiene and Safety
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• v.18 no.3
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• pp.95-100
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• 2003

Competitive direct enzyme-linked immunosorbent assay(cdELISA) of aflatoxin $B_1$ ($AFB_1$) in deonjang(Korean-style soybean paste) and kochujang(fermented hot peppersoybean paste) and the level of $AFB_1$ in modern or traditional style deonjang and gochujang, produced in Korea, was surveyed by cdELISA. From the standard curve of the cdELISA, the detection limit of $AFB_1$ was 0.2 ng/m/. The average recovery of $AFB_1$ was 71.5% in the range of 1~100 ng/g after spiking $AFB_1$ into deonjang and it means that it could be possible to detect the $AFB_1$ in these range by the cdELISA in deonjang. Among the 30 kochujangs tested, no $AFB_1$ was detected in kochujangs. Among the 30 deonjangs, $AFB_1$ was detected in 6 ones in the range of 1.0~6.0 ng/g. The occurrence of $AFB_1$ in deonjang and kochujang tested in this study was less than the Korea Standard and Specification of aflatoxin in foods (10 ppb).

• Journal of Life Science
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• v.20 no.5
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• pp.697-702
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• 2010

Ten farrow-finish farms participated in this seromonitoring that was conducted to investigate the porcine brucellosis situation in Korea. In total, eight (80.0%) of the 10 farms and 139 (24.0%) of 578 pigs tested showed a positive response in the Rose Bengal test (RBT). Seroprevalence levels were determined using RBT according to age; 35 (14.6%) of 239 piglets, 36 (31.3%) of 115 growing pigs, and 68 (30.4%) of 224 finishing pigs and sows were positive, respectively. All positive samples in RBT were tested with the tube agglutination test (TAT) and competitive ELISA (C-ELISA), simultaneously. Although 48 samples came up positive in the TAT, all samples tested with C-ELISA were negative. Among 26 rectal swab samples from the TAT positive-pigs, Yersinia enterocolitica O:9 was isolated from seven samples (26.9%). Therefore, we speculated that the positive reaction of RBT and TAT in this study might be induced by the serologically cross-reacting bacteria with Brucella abortus.

• Korean Journal of Food Science and Technology
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• v.32 no.5
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• pp.991-996
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• 2000

Enzyme-linked immunosorbent assay was developed for the analysis of soy protein in foods. Competitive indirect ELISA (ciELISA) was established by using specific antibodies against the heat-stable acidic subunits (AS) of glycinin. Soy proteins in each sample used in this study were solublized in the presence of urea and DTT and boiled at $100^{\circ}C$ for 1hr and then were renatured with a cystine-containing solution. After these treatments, each isolated soy protein (ISP) heated at 60, 70, 80, $90^{\circ}C$ for 10 minutes showed almost the same curve as unheated one in the ciELISA. The detection limit of ISP was 0.3 ${\mu}g/mL$. Anti-AS antibodies have very low reactivities less than 0.1% toward non-meat proteins such as skim milk and casein and did not show any reactivities toward egg white powder and ovalbumin. When laboratory-made sausages containing ISP of $0.5{\sim}3%$ were assayed by ciELISA, the mean recovery was about 83% (C.V., 19%). In addition, the average content of soy protein in commercial sausages was 1.27%.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.407.1-407.1
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• 2002

To develop immunostrip of DDT (4.4'-dichlorodiphenyl-2.2,2-trichloroethane) and its metabolites, DDT derivatives (DDA-. DDHP-. DDCP-. DDHH-. and DDHHAP-) were conjugated to carrier proteins (OVA and BSA) and three DDT derivatives (DDA. DDHP. DDCP) were conjugated to KLH for the use of coating ligand and immunogen. respectively. To screen the immunoreactivity of antibody to DDT derivatives, the coating ligand was evaluated by a competitive ELISA and DDHP-OVA was selected. (omitted)