• Microbiology and Biotechnology Letters
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• v.20 no.2
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• pp.225-232
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• 1992

In order to develop an enzyme-linked immunosorbent assay(ELISA) for detecting aflatoxin $B_1(AFB_1)$, we produced and purified antibodies, thereafter established and evaluated methods of direct and indirect competitive ELISA. Anti-AFB, antisera, produced by immunizing rabbits with $AFB_1$-1-(0-carboxymethy1)oxime-bovine serum albumin conjugate ($AFB_1$-BSA), were removed of anti-BSA antibodies by quantitative precipitation reaction and further purified by ammonium sulfate precipitation and DEAE-Sephadex A-50 ion exchange chromatography. Purified IgG fractions were used as anti-$AFB_1$ antibodies. The antibodies, whose titer was deterrnined extremely high above $2 \times 10^6$, showed low cross-reactivity of 3~34% against $AFB_1$ analogues such as G2, B2, and GI. From the standard curves of direct and indirect competitive ELISA for AFBI, the detection ranges were found 0.2~20 and 1~10, 000 ng/ml(ppb) respectively. In their sensitivity, stability, simplicity, and rapidity, the direct method was more suitable than the indirect method for practical use.

• Korean Journal of Veterinary Research
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• v.41 no.1
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• pp.89-98
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• 2001

This study was conducted to detect the toxoplasma specific-DNA in circulating blood and organs collected from slaughtered pigs at slaughtering house and experimentally infected pigs with Toxoplasma gondii tachyzoites by polymerase chain reaction(PCR), and also PCR was applied to diagnose for acute phase of swine toxoplasmosis as a newly developed diagnostic test. The sensitivity of oligonucleotide primer, T-1 & T-2, designed from toxoplasma B1 gene amplification method was compared with Tp parasite detection by mouse inoculation(MI). On the other hand, latex agglutination test(LAT) was conducted to detect the serum antibodies comparing with the detection of toxoplasma by PCR and MI. The results obtained were summarized as follows. PCR was able to determine at the lowest level of $10^0/ml$ T. gondii in blood samples which were blended with a serial diluted T gondii in vitro. On the other hand, $10^2/5g$ of T gondii could detect from a variety of tissues including lung, diaphragm, liver, heart, spleen and brain in vitro. The primer was proved to specifically determine T gondii in blood and tissues in vitro but it did not detect Neospora caninum used as a negative control. DNA of T. gondii was effectively extracted by freezing, thawing and grinding twice both tissues mixed with T gondii in vitro and in experimentally infected pig's tissues. PCR detected specific DNA in the blood of experimentally infected pigs at 108 hrs and 120 hrs post-infection, it was the same time that the pigs showed fever and parasitaemia. In case of tissue, specific DNA was, however, detected only lung from experimentally infected pigs. Even though the duration of acute phase was from 3 to 7 days post-infection, but the latex agglutination test (LAT) results appeared from 8 days post-infection. A comparison of sensitivity in determining T gondii in blood samples between PCR and MI, PCR positive rate ranged from 25 to 33.3%, but that of MI covered from 75 to 100%.

• Journal of Mushroom
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• v.18 no.1
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• pp.84-90
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• 2020

Wild-type isolates of H. erinaceus were collected from different geographical areas of Korea. Nineteen isolates were cultured on mushroom substrate for producing fruiting bodies. Of these, 14 isolates formed pinheads and fruiting bodies on the substrate. The morphological and cultivation characteristics of fruiting bodies were categorized by pinheading, fruit body formation, spine types, fresh weights, and colors. Microstructures, including spines, spores, and basidia on the fruiting bodies were observed using scanning electron microscopy. The H. erinaceus isolates demonstrated different PCR polymorphisms produced by universal fungal primers (UFPs) and were classified into four groups based on their high genetic diversity.

• Journal of Mushroom
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• v.17 no.4
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• pp.185-190
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• 2019

Pleurotus ostreatus No.42, known as the ligninolytic basidiomycetes, showed production of MnP and Lac, but did not show any LiP acitivity in static culture, grown in GPYW liquid medium. Maximum production of MnP (80U/flask) was observed on day 11 of culturing in this medium. Chromatographic purification of MnP included the use of Sepharose CL-6B and Mono-Q. The major MnP isozyme purified by column chromatography was observed to be a 36.4 KDa (single band on SDS PAGE). The 19-amino acid sequence from the N-terminal was determined by protein sequencing to be ATCADGRTTANAACCVLFP. The N-terminal sequence of the major MnP isozyme of P. ostreatus No.42 was found to be the same as a previously reported sequence of an MnP3 isozyme from this fungus.

• Journal of Sensor Science and Technology
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• v.22 no.2
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• pp.144-149
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• 2013

In this research, we developed a biosensor to detect lung cancer-specific biomarker using Anodic Aluminum Oxide (AAO) chip based on interference and nano surface plasmon resonance (nanoSPR). The nano-porous AAO chip was fabricated $2{\mu}m$ of pore-depth by two-step anodizing method for surface uniformity. NanoSPR has sensitivity to the refractive index (RI) of the surrounding medium and also provides simple and label-free detection when specific antibodies are immobilized to the Au-deposited surface of nano-porous AAO chip. To detect the lung cancer-specific biomarker, antibodies were immobilized on the surface of the chip by Self Assembled Monolayer (SAM) method. Since then lung cancer-specific biomarker was applied atop the antibodies immobilized layer. The specific reaction of the antigen-antibody contributed to the change in the refractive index that cause shift of resonance spectrum in the interference pattern. The Limit of Detection (LOD) was 1 fg/ml by using our nano-porous AAO biosensor chip.

• Korean Journal of Veterinary Research
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• v.14 no.2
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• pp.243-252
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• 1974

The experiment was performed in order to investigate the applicability of the rapid detection of salmonellae in various animal-origin foods by means of the direct fluorescent antibody technique. Egg, sausage and chicken were inoculated with various concentrations of Sal.paratuphi A, Sal. paratyhi B and Sal. thompson, and the fluorescent antibody technique was applied and compared with the conventional cultura method for the sensitivity of detection of the organisms. Two methods were employed in the fluorescent antibody technique; the direct smear method in which the smear being made directly from the specimens, and the enrichment smear method in which the smear being made from the enrichment broth. The effect of various enrichment time (1,5,8,11 and 13 hours) in tetrathionate broth on the detection of salmonellae in the fluoresent antibody technique was also studied. The results obtained were summarized as followings; 1. Of the three methods, the enrichment smear method of fluorescedt antibody technique was highly effective as cultural method for the detection of salmonella organisms. 2. Direct smear method of fluorescent antibody technique was effective as two other methods $5{\times}10^4$ organisms presented in 50 g(ml) of specimens. This method may not be applicable when the specimens contained $5{\times}10^2$ or less organisms. 3. Of the three specimens, the recovery rate of Salmonella organisms from egg was slightly higher than that of sausage and chicken. 4. In fluorescent antibody technique and cultural method, the specimens inoculated with Sal. thompson were found to be higher detection rate than the specimens inoculated with Sal. paratyphi A, 5. The optimum enrichment time of Salmonella organisms in tetrathionate broth on the detection by fluorscent antibody technique was found to be 11 hours or longer when the specimens of egg, sausage and chicken were inoculated with approximately 500 organisms. The longer enrichment time was the higher detection rate up to 11 hours tested.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.4
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• pp.381-387
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• 1991

Andong Sickhae is a traditional Korean fermented rice product which is made from glutionous rice, male, radish, ginger and red pepper. The changes in chemical composition, pH, amino nitrogen, amino acid, enzyme activity and free sugar of a traditional Andong Sickhae were monitored during the fermentation and storage at $4^{\circ}C$. The changes in ash, crude fat and moisture the contents during Andong Sickhae fermentation and storage were negligible. The pH of the product tended to decrease in the course of fermentation and storage and it showed the minimum value of 3.90 after 20th day of storage. On the other hand the maltose continued to increase up from 6.35g to 9.85g/100ml by 15th day of storage. The content of amino nitrogen in Andong Sickhae gradualy increase up to 22.40mg% by 3th day of fermentation. Glutamic aicd and aspartic acid were the major amino acid in water and salt soluble protein in Andong Sickhae.

• Journal of the Korean Chemical Society
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• v.21 no.6
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• pp.427-433
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• 1977

A neutron activation method has been developed for the simultaneous determination of chromium, iron, lanthanum, scandium and zinc in river-water samples. The sample is sealed in the silica ampoule without pretreatment and irradiated for a week at a thermal neutron flux of $1{\times}10^{13}n{\cdot}cm^{-2}{\cdot}sec^{-1}$. After cooling for about two days, the elements in the sample are sequentially extracted at different pH by 0.1M oxine-chloroform solution. The organic layers are checked by Gamma-ray spectrometry with $″3\;{\times}\;3″$ NaI (T1) detector connected to a 800-channel pulse hight analyzer. The ppb concentration of the elements in most of river-water samples could be determined by this method. The tracer study for the quantitative separation of the elements was also carried out.

• Journal of Aquaculture
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• v.2 no.1
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• pp.43-51
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• 1989

Fatty acid contents were measured in the cultures of the flagellate green algae Dunaliella tertiolecta Butcher under different conditions of light intensity, duration of light, and temperature. Duration of light and temperature, in particular, affected the growth rate of D. tertiolecta. The maximun cell number reached $2.32{\times}10^6$ cells/ml. The division rate per day was 1.97 in the exponential phase. The analysis of fatty acids obtained from various conditions showed that the lipid mainly contained C16, C18:3$\omega$3 fatty acids and there was no significant level of polyunsaturated fatty acids such as EPA and DHA. Polyene fatty acid increased with decreasing temperature and light intensity did not influence on fatty acid composition. The increasing duration of light enhanced the growth of D. tertiolecta, whereas polyene($\omega$3) slightly increased with decreasing the light period.

• Korean Journal of Agricultural Science
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• v.39 no.4
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• pp.613-618
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• 2012

This study was performed to optimize the basic platform of a lateral flow immunoassay. Improvement of the limit of detection (LOD) was evaluated according to the width of a nitrocellulose membrane with varying concentrations of analyte. The analyte, neutravidin was detected based on the avidin-biotin interaction. The antibody-Au nanoparticle conjugation was mostly stabled in a PBS buffer of pH 7.3. The optimal widths of a nitrocellulose membrane were 4 and 6 mm considering the sample flow rate and signal strength of the test line on the membrane. The LOD of neutravidin was 0.001 mg/ml in the optimum conditions.