• Korean Journal of Food Science and Technology
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• v.32 no.3
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• pp.564-569
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• 2000

An enzyme-linked immunosorbent assay(ELISA) was developed for the detection of milk proteins in processed foods. The ${\alpha}_{s1}-casein({\alpha}_{s1}-CN)$, a heat stable major milk protein, was immunized into rabbits to produce specific antibodies. When competitive indirect ELISA(ciELISA) using $anti-{\alpha}_{s1}-CN$ antibodies was established, its detection limit was $0.1\;{\mu}g/mL$. The reactivities of the specific antibodies toward ${\alpha}_{s1}-CN$, skim milk, ${\beta}-CN$ and whey protein isolate(WPI) were 100, 37, 0.14 and 0.04%, respectively, as determined by ciELISA. However $anti-{\alpha}_{s1}-CN$ antibodies did not have any reactivity to other milk proteins such as ${\beta}-lactoglobulin,\;{\alpha}-lactalbumin$, bovine serum albumin, and isolated soy protein. When sandwich ELISA was established, its detection limit was $0.01\;{\mu}g/mL$ which was 10 times more sensitive than that of ciELISA. In the spike test which was performed by adding 1-10% of whole CN to market milk, mean assay recovery as determined by sandwich ELISA was 94.8%(CV, 8.2%). Food stuffs and dairy products were assayed by sandwich ELISA to show 29, 0.13, 0.25, and 6.9% of whole CN in skim milk powder, WPI, semi-solid yoghurt, and processed cheese, respectively.

• Korean Journal of Food Science and Technology
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• v.30 no.6
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• pp.1273-1278
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• 1998

Conditions for enzyme-protein binding assay (EPBA) were established in order to detect biotin more rapidly and reproducibly than traditional microbiological assay (MBA). EPBA with streptavidin and biotin-KLH conjugate showed cross-reactivities on biocytin, a derivative with biotin activity, at the rate of 109% $(IC_{50}=0.3\;ppb)\;and\;197%\;(IC_{50}=0.8\;ppb)$, respectively, but not on other derivatives with no biotin activities, such as desthiobiotin, diaminobiotin and 2-iminobiotin. Detection ranges of biotin by EPBA with streptavidin and biotin-KLH conjugates were $0.01{\sim}30\;ng/mL\;and\;0.01{\sim}1.0\;ng/mL(ppb)$, respectively. In the spike test with milk, fruit flake and pine-carrot juice, the correlation coefficience between MBA and EPBA with biotin-KLH conjugates was r=0.994. But MBA showed cross-reactivities both on biocytin and desthiobiotin at the rate of 80.1% and 66.7%, respectively. Detection range of biotin by MBA was $0.1{\sim}0.5\;ng/mL(ppb)$. These results strongly suggest that EPBA is efficient for biotin detection in sensitivity, detection range, cross-reactivity and time consuming.

• Food Science of Animal Resources
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• v.30 no.1
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• pp.36-41
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• 2010

The Hen's egg is widely used in many processed foods as an ingredient and is one of the most prevalent food allergens in children. To detect egg proteins in processed foods, we developed a competitive indirect enzyme-linked immunosorbent assay (ciELISA) using an anti-ovomucoid (OM) antibody, which was produced by immunization of rabbits with OM, the most heat-stable component of the egg proteins. The detection limit of this quantitative assay system was 30 ng/mL. Cross-reactivity of the anti-OM antibody toward OM, ovalbumin, skim milk, casein, whey protein isolate, and isolated soy protein was 100, 0.4, 0.2, 0.04, 0, and 0%, respectively. In the spike test of egg white powder in milk replacer, commercial sausage, and in-house sausage, the assay recoveries ($mean{\pm}SD$) were $129{\pm}13.7%$, $73.9{\pm}12.5%$, and $65.5{\pm}13.6%$, respectively. When egg white in a commercial crab meat analog and sausage was determined by ciELISA, the assay recovery was found to be 108% and 127%, respectively. The combined results of this study indicate that this novel ciELISA for OM detection could be applied for the quantification of hen's egg proteins in processed foods.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.6
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• pp.1152-1159
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• 1998

In order to develop more rapid and reproducible analysis of biotin known as vitamin H, attempts were made to establish the condition for enzyme linked immunosorbent assay(ELISA) compared with traditional microbiological assay(MBA). Antibiotin and antiserum were obtained from the immunized rabbits injected with emulsion of biotin KLH conjugate and Freund's adjuvant. The antiserum showed cross reactivity on biocytin, a derivative of biotin, which is converted to biotin in intestine, at the rate of 177%(median inhibitory concentration(IC50)=12.58ppb), but not on other derivatives such as desthiobiotin, diaminobiotin and 2 imino biotin. Specific antibody for biotin was purified from the antiserum through protein A column and desalting column. The conditions of competitive direct ELISA (cdELISA) were established. Detection range of biotin concentration by cdELISA was 0.01∼300ng/ ml(ppb). In the spike test with milk, fruit flake and pine carrot juice, the correlation coefficient between two methods of MBA and ELISA was reliably consistent at the value of r=0.992. But detection of biotin by microbiological assay(MBA) was rather restricted in range and nonspecific. Detection range of biotin by MBA was 0.1∼0.5ng/ml(ppb). It showed cross reactivities on biocytin and desthiobiotin at the rate of 80.1% and 66.7%, respectively. In conclusion, ELISA revealed a significant improvement compared with MBA for the biotin detection in terms of sensitivity, detection range and cross reactivity. In addition, a variety of samples could be analyzed rapidly and conveniently at one time by using ELISA. These results strongly suggest that the ELISA is very promising for the practical application to detect biotin contents in a wide range of food stuffs.

• The Plant Pathology Journal
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• v.34 no.2
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• pp.104-112
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• 2018

Accurate and rapid detection of bacterial plant pathogen is the first step toward disease management and prevention of pathogen spread. Bacterial plant pathogens Clavibacter michiganensis subsp. nebraskensis (Cmn), Pantoea stewartii subsp. stewartii (Pss), and Rathayibacter tritici (Rt) cause Goss's bacterial wilt and blight of maize, Stewart's wilt of maize and spike blight of wheat and barley, respectively. The bacterial diseases are not globally distributed and not present in Korea. This study adopted comparative genomics approach and aimed to develop specific primer pairs to detect these three bacterial pathogens. Genome comparison among target pathogens and their closely related bacterial species generated 15-20 candidate primer pairs per bacterial pathogen. The primer pairs were assessed by a conventional PCR for specificity against 33 species of Clavibacter, Pantoea, Rathayibacter, Pectobacterium, Curtobacterium. The investigation for specificity and sensitivity of the primer pairs allowed final selection of one or two primer pairs per bacterial pathogens. In our assay condition, a detection limit of Pss and Cmn was $2pg/{\mu}l$ of genomic DNA per PCR reaction, while the detection limit for Rt primers was higher. The selected primers could also detect bacterial cells up to $8.8{\times}10^3cfu$ to $7.84{\times}10^4cfu$ per gram of grain seeds artificially infected with corresponding bacterial pathogens. The primer pairs and PCR assay developed in this study provide an accurate and rapid detection method for three bacterial pathogens of grains, which can be used to investigate bacteria contamination in grain seeds and to ultimately prevent pathogen dissemination over countries.

• Journal of Microbiology and Biotechnology
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• v.24 no.10
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• pp.1445-1454
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• 2014

Severe acute respiratory syndrome (SARS), a disease that spread widely in the world during late 2002 to 2004, severely threatened public health. Although there have been no reported infections since 2004, the extremely pathogenic SARS coronavirus (SARS-CoV), as the causative agent of SARS, has recently been identified in animals, showing the potential for the re-emergence of this disease. Previous studies showed that 27 single nucleotide polymorphism (SNP) mutations among the spike (S) gene of this virus are correlated closely with the SARS pathogenicity and epidemicity. We have developed a SNP DNA microarray in order to detect and genotype these SNPs, and to obtain related information on the pathogenicity and epidemicity of a given strain. The microarray was hybridized with PCR products amplified from cDNAs obtained from different SARS-CoV strains. We were able to detect 24 SNPs and determine the type of a given strain. The hybridization profile showed that 19 samples were detected and genotyped correctly by using our microarray, with 100% accuracy. Our microarray provides a novel method for the detection and epidemiological surveillance of SARS-CoV.

• Atmosphere
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• v.26 no.4
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• pp.541-551
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• 2016

A real-time quality control algorithm for $PM_{10}$ concentration measured by Continuous Ambient Particulate Monitor (FH62C14, Thermo Fisher Scientific Inc.) has been developed. The quality control algorithm for $PM_{10}$ data consists of five main procedures. The first step is valid value check. The values should be within the acceptable range limit. Upper ($5,000{\mu}g\;m^{-3}$) and lower ($0{\mu}g\;m^{-3}$) values of instrument detectable limit have to be eliminated as being unrealistic. The second step is valid error check. Whenever unusual condition occurs, the instrument will save error code. Value having an error code is eliminated. The third step is persistence check. This step checks on a minimum required variability of data during a certain period. If the $PM_{10}$ data do not vary over the past 60 minutes by more than the specific limit ($0{\mu}g\;m^{-3}$) then the current 5-minute value fails the check. The fourth step is time continuity check, which is checked to eliminate gross outlier. The last step is spike check. The spikes in the time series are checked. The outlier detection is based on the double-difference time series, using the median. Flags indicating normal and abnormal are added to the raw data after quality control procedure. The quality control algorithm is applied to $PM_{10}$ data for Asian dust and non-Asian dust case at Seoul site and dataset for the period 2013~2014 at 26 sites in Korea.

• The Korean Journal of Physiology and Pharmacology
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• v.15 no.6
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• pp.415-422
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• 2011

Previously, we reported that besides retinal ganglion cell (RGC) spike, there is ~10 Hz oscillatory rhythmic activity in local field potential (LFP) in retinal degeneration model, rd1 mice. The more recently identified rd10 mice have a later onset and slower rate of photoreceptor degeneration than the rd1 mice, providing more therapeutic potential. In this study, before adapting rd10 mice as a new animal model for our electrical stimulation study, we investigated electrical characteristics of rd10 mice. From the raw waveform of recording using $8{\times}8$ microelectrode array (MEA) from in vitro-whole mount retina, RGC spikes and LFP were isolated by using different filter setting. Fourier transform was performed for detection of frequency of bursting RGC spikes and oscillatory field potential (OFP). In rd1 mice, ~10 Hz rhythmic burst of spontaneous RGC spikes is always phase-locked with the OFP and this phase-locking property is preserved regardless of postnatal ages. However, in rd10 mice, there is a strong phase-locking tendency between the spectral peak of bursting RGC spikes (~5 Hz) and the first peak of OFP (~5 Hz) across different age groups. But this phase-locking property is not robust as in rd1 retina, but maintains for a few seconds. Since rd1 and rd10 retina show phase-locking property at different frequency (~10 Hz vs. ~5 Hz), we expect different response patterns to electrical stimulus between rd1 and rd10 retina. Therefore, to extract optimal stimulation parameters in rd10 retina, first we might define selection criteria for responding rd10 ganglion cells to electrical stimulus.

• Journal of Veterinary Clinics
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• v.20 no.2
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• pp.150-154
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• 2003

A disease with severe diarrhea occurred in a herd of one thousand, 1-week-old piglets in Chinju, Korea, and was diagnosed as porcine epidemic diarrhea by the detection of N gene of porcine epidemic diarrhea virus (PEDV) from small intestines. A PEDV, named as Chinju99, was also isolated from the intestines after two blind-passages in Vero cells supplemented with trypsin (10 ug/ml). and the biological and physicochemical properties of the isolate were characterized. The virion was roughly spherical in shape and had spike peplomers on its outer surface. The virus exhibited cytopathic effects such as rounding degeneration at initiation of infection and syncytia formation later in Vero cells. The virus was labile to 20% ether and 5% chloroform but stable in acid with pH 4-7 at $4^{\circ}C$. The infectivity of the virus was maintained at $50^{\circ}C$ for 180 min, and the buoyant density of the virus in sucrose was 1.180 g/ml. All biological and physicochemical properties of the virus were typical features of coronaviruses.

• Korean Journal of Veterinary Service
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• v.19 no.2
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• pp.163-171
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• 1996

This study was carried out to determination of carbadox and olaquindox residues in swine tissues by MSPD(matrix solid phase disperse)method. The results obtained were as follows ; 1. Optimal wavelengths of UV for carbadox and olaquindox were 310 and 370nm, respectively 2. Ethyl acetate-Acetonitrile(8:2) was found to be adequate as extractant in this method. 3. The average overall recovery of carbadox at the 0.01, 0.05, and 1.0PPM spike levels was 89. 2% and that of olaquindox was 89.9%, and the detection limits were 0.5ng for carbadox and olaquindox.