• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.33 no.1
• /
• pp.55-59
• /
• 2000

A specific and sensitive sandwich enzyme-immunoassay (EIA) using Avidin-Biotin complex was developed for the measurement of GTH II levels in pituitary content and pituitary cell culture medium of the rainbow trout-(Oncorhpchus mykiss). Biotin-salmon GTH II rabbit IgG (sefondary antibody) wai purified by a protein A sepharose affinity chromatography column and that was biotinylated by using Biotin-N-hydroxysuccinimide ofter (BNHS). Non-biotin salmon GTH II rabbit IgG (first antibody) was obtained only through a protein A sepharose affinity chromatography column. The assay was performed by the so-called 'sandwich' method using a microtiter plate, A dose-response curve was obtained between $0.12 to 125 ng/ml$ of salmon GTH II. The displacement curves for pituitary extraction and pituitary cell culture medium of testosterone-treated rainbow trout were Parallel to the standard curie. The intra-assay and inter-assay coefficients of variation (CV) were $8.2{\%} (N=5) and 12.5{\%} (N=6)$, respectively, This assay system was used to measure the amount of GTH II that accumulated in the culture medium of dispersed pituitary cells in testosterone-treated immature rainbow trout, The accumulation was increased with the amount or salmon gonadotropin-releasing hormone. GTH II values determined by the present method were well correlated with those determined by radioimmunoassay. As a result, this assay system was found to be suitable for the measurement of GTH II for pituitary extraction and pituitary culture medium in many salmonid fishes.

• The Journal of the Korean Society for Microbiology
• /
• v.21 no.3
• /
• pp.387-391
• /
• 1986

Serum samples from 51 patients with clinically suspected typhoid fever were tested for immunoglobulin G (IgG), IgM and IgA antibodies against the whole bacteria antigen of Salmonella typhi by an enzyme-linked immunosorbent assay. The levels of IgG and IgA antibody to-whole bacteria antigen were higher in the culture-proven patients than in controls. The levels of IgM antibody to- whole bacteria antigen showed better discrimination between culture negative patients and controls than those of IgG or IgA antibody to-whole bacteria antigen. The enzyme-linked immunosorbent assay was much more sensitive than the Widal test. It would be a useful tool for the diagnosis of typhoid fever with a single serum sample.

• Journal of Microbiology and Biotechnology
• /
• v.10 no.2
• /
• pp.251-257
• /
• 2000

Chitin synthases are identified as key enzymes of chitin biosynthesis in most of the fungi. Among them, chitin synthase II has been reported to be and essential enzyme in chitin biosynthesis, and exists as a membrane-bound form. To search and screen new antifungal agents from natural resources to inhibit chitin synthase II, the assay conditions were established using the enzyme isolated from Saccharomyces cerevisiae ECY38-38A(pAS6) that overproduces only chitin synthase II. This enzyme was activated only by partial proteolysis with trypsin. Its actibity reached the maximum at $80{\;}\mu\textrm{g}/ml$ of trypsin and was strongly stimulated by 2.0 mM $Co^{2+}$, 1.0 nM UDP-[$^{14}C$]-GicNAc, and 32 mM free-GlcNAc. Under these assay conditions, the highest chitin synthase II activity was observed by incubation at $30^{\circ}C$ for 90 min. However, and extremely narrow range of organic solvents up to as much as 25% of DMSO and 25% of MeOH was useful for determining optimal assay conditions. After a search or potent inhibitors of chitin synthase II from natural resources, prodigiosin was isolated from Serratia marcescens and purified by solvent extration and silica gel column chromatographies. The structure of prodigiosin was determined by UV, IR, Mass spectral, and NMR spectral analyses. Its molecular weight and formula were found to be 323 and $C_{20}H_{25}N_{3}O$, respectively. Prodigiosin ingibited chitin synthase II by 50% at the concentration of $115{\;}\mu\textrm{g}/ml$.

• Parasites, Hosts and Diseases
• /
• v.26 no.1
• /
• pp.27-32
• /
• 1988

The applicability of indirect immunoftuorescent antibody test (IFAT) was compared with enzyme-linked immunosorbent assay (ELISA) in sera from 163 cases of confirmed neurocysticercosis, 101 other neurologic and parasitic diseases and 100 normal controls. As antigen, frozen sections of a Taenia solium metacestode from a human brain was used in IFAT and cystic fluid was used in ELISA. For the detection of specific IgG antibody, IFAT was equally sensitive (89.6%) and specific (85.1%) as ELISA. The antibody titers by IFAT were correspondingly increased with mean absorbance of ELISA. The corresponding rate of positivity in the two techniques was 90.8%. Except for the difficulty in detecting antibodies in cerebrospinal fluid (CSF), IFAT was concluded to be very useful for the serodiagnosis of human neurocysticercosis.

• Asian-Australasian Journal of Animal Sciences
• /
• v.28 no.5
• /
• pp.691-696
• /
• 2015

The objective of this study was to evaluate the quality of five commercial enzyme linked immunosorbent assay (ELISA) kits (A, B, C, D, and E) from different suppliers for detecting aflatoxin $B_1$ ($AFB_1$). $AFB_1$-free corn samples supplemented with different levels of $AFB_1$ (5, 10, and $20{\mu}g/kg$) were used as positive controls and 6 replicates of each control sample were tested to evaluate the accuracy and precision of these kits. In addition, we also evaluated the performance of these ELISA kits for $AFB_1$ in 30 feed samples, including corn, distillers dried grains with soluble, wheat samples, soybean meal, and poultry feed, which were verified by high performance liquid chromatography. Results showed that the coefficients of variation ranged from 1.18% to 16.22% in intra-plate and 2.85% to 18.04% in inter-plate for the determination of $AFB_1$. The half maximal inhibitory concentration for five kits ranged from 3.72 to $7.22{\mu}g/kg$. The quantitation limits of $AFB_1$ were all under the legal limit in China but somewhat inconsistent with kit instructions. Although the recovery rate of four of the five kits were either less than 90% or more than 110%, all these values were acceptable in practice. Two kits had high false positive rates (C and E). In conclusion, our results revealed that the qualities of five tested ELISA kits were significantly different.

• Environmental Analysis Health and Toxicology
• /
• v.5 no.3_4
• /
• pp.29-36
• /
• 1990

Aflatoxins, produced by strains of Aspergillus flavus and Aspergillus parasiticus, can be found worldwide in corn, barley, peanuts, and other commodities. Among this group of toxins, aflatoxin B$_1$was realized to be one of the most potent environmental carcinogens, mutagens and teratogens. It is routinely monitored by methods such as thin layer chromatography, liquid chromatography, fluorodensitometric technique and radioimmunoassay. However, these assays are expensive, necessitate radioactive reagents, and require overnight incubation. In this study, the determination of fungal flora in several sorts cereals has been carried out in order to obtain an appropriate information of the population of fungi. The quantitative analysis of aflatoxin B$_1$has been carried out by High Performance Liquid Chromatography (HPLC) method and Enzyme Linked Immunosorbent Assay (ELISA). The results were summarized as follow: 1) From the 100 samples,313 colonies of fungi were isolated. Among the 313 colonies, 274 were possible to identify into 11 genera. The identified genera were Aspergillus Penicillium, Mucor, Rhizopus, Alternaria, Cladosorium, Fusarium, Circinella, Chrysosporium, Paecilomyces and Phoma. 2) Six of Aspergillus flavus were aflatoxin-producing strains. Aspergillus flavus isolated from sample barleys was contained the highest content (21.8 $\mu\textrm{g}$/ml) of aflatoxin B$_1$. 3) The yield of aflatoxin B$_1$-oxime compound was appromately 75%. Aflatoxin B$_1$-oxime-Human serum albumin was approved by formal consent as complete antigen. 4) Direct competitive ELISA permitted detection of 0.15 ng levels. In the quantitative microanalysis, ELISA was superior to HPLC method.

• Korean Journal of Veterinary Research
• /
• v.37 no.3
• /
• pp.613-618
• /
• 1997

Direct competitive enzyme linked immunosorbent assay(ELISA) with monoclonal antibodies have been studied for quantitative determination of T-2 toxin from the mold corn. The T-2HS, T-2HS-BSA, T-2HS-HRP and monoclonal antibodies against T-2 toxin produced in the studies were qualified for quantitative ELISA test of T-2 toxin. The mean recovery rate from ground com spiked T-2 toxin was 83%. The meaning range of the T-2 test was 60ng to $2{\mu}g$. According to the recovery results with the com spiked T-2, the tests proved to be suitable in the screening of the moldy feed samples for the presence of T-2 toxin and will be able to become the basis of the ELISA test for the quantitative screening kits of T-2 toxin.

• Korean Journal of Food Science and Technology
• /
• v.32 no.3
• /
• pp.538-543
• /
• 2000

This study was conducted to develop an enzyme-linked immunosorbent assay(ELISA) for the determination of cooked goat meat. Muscle proteins were extracted from goat meat by heating at $98^{\circ}C$ for 15 min. Major thermostable(TS) protein, whose size and pI are 36 and 38 kDa and 4.5 respectively, were purified by DEAE-Sephadex A-50 and Sephadex G-75 column chromatography. The TS protein was immunized into rabbits in order to produce goat specific antibodies. Competitive indirect ELISA(ciELISA) was established by using the anti-TS antibody. The antibody showed high reactivity toward the TS antigen and the boiled goat meat extract but it did not show any reactivities toward extracts of boiled chicken, pork, lamb, and beef. Thus, this ciELISA developed in this study could be applicable to identify goat species from cooked meat.

• The Journal of the Korean Society for Microbiology
• /
• v.22 no.2
• /
• pp.117-123
• /
• 1987

Previous studies have been performed for the sero-identification of selected species of Bacteroides by immunofluorescence antibody techniques and enzyme-linked immunosorbent assay using species-specific rabbit antisera to B. gingivalis, B. intermedius, and B. melaninogenicus. However, these studies have not commented on the serological cross-reactivity between these 3 species of black- pigmented Bacteroides. For the cross-reactivity study, antisera to B. gingivalis ATCC 33277, B. intermedius ATC C25261 and B. asaccharolyticus ATCC 25260 were raised from rabbits. Preliminary study for observing the cross-reactivity between these species was performed by indirect immunoflourescence technique. Immunoabsorption of the antisera was done with bacterial cells from the other species and the species-specificity of the antisera was conformed by the absence of reactivity with bacterial strains from the other species by indirect immunofluorescence technique and enzyme-linked immunosorbent assay. Three representative unabsorbed antisera cross-reacted strongly with cells from the other species. Especially, anti-B. asaccharolyticus ATCC 25260 antiserum showed a strong cross-reactivity with B. gingivalis ATCC33277. After immunoabsorption of 3 representative antisera with the other species, the cross-reactivity was found only between B. gingivalis ATCC 33277 and B. asaccharolyticus ATCC 25260. Further study would be necessary to clarify the cross-reactivity between important oral black-pigmented Bacteroides from subgingival plaque or bacterial colonies for rapid identification.

• Animal Bioscience
• /
• v.34 no.12
• /
• pp.1995-2002
• /
• 2021

Objective: Detection of adulteration in processed meats is an important issue for some countries due to substitution of beef with a cheaper source of protein like poultry. In this study, the presence of chicken meat was investigated using real-time polymerase chain reaction (real-time PCR) and enzyme-linked immunosorbent assay (ELISA) techniques to verify adulteration of fermented sausage samples. Methods: A total of 60 commercial samples were collected from 20 establishments in three replicates including 10 fermented sausage manufacturers and 10 butchers to investigate the presence of chicken meat with the sequential use of real-time PCR and ELISA techniques. In addition, pH, moisture content, water activity and color values of the samples were determined. Results: Both real-time PCR and ELISA showed agreement on the presence or absence of chicken meat in 55 out of 60 fermented sausage samples and chicken meat was identified with both methods in 16 samples. Five samples produced inconsistent results for the presence of chicken meat in the first run. Nevertheless, the presence of chicken meat was verified with both methods when these samples were analyzed for the second time. In addition, the average physico-chemical values of the fermented sausage samples tested positive for chicken meat were not significantly different from some of those fermented sausage samples tested negative for the chicken meat. Conclusion: The sequential use of real-time PCR and ELISA techniques in fermented sausages could be beneficial for the government testing programs to eliminate false negatives for detection of adulteration with chicken meat. Furthermore, consumers should not rely on some of the quality cues including color to predict the adulteration of fermented sausages with chicken meat since there were no statistical differences among some of the samples tested positive and negative for chicken meat.