• BMB Reports
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• v.28 no.6
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• pp.504-508
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• 1995

The electrophoretic patterns of plasma membrane surface proteins of normal rat liver cells and rat hepatomas were compared in 10% non-denaturing and 7-15% gradient non-denaturing gel. Chemical carcinogens, 2-Me DAB (2-methyl-4-dimethylaminoazobenzene) and DENA (diethylnitrosamine), were used to induce hepatoma in rats. One protein which disappeared in hepatoma was identified in normal rat liver by non-denaturing gel electrophoresis. Rabbit antisera were raised against this specific protein, and the protein was purified by Sephacryl S-200 column and immunoaffinity chromatography using the purified antibody. The purified protein showed two bands of molecular weights approximately 50 $kD_{\alpha}$ and 52 $kD_{\alpha}$ by SDS-polyacrylamide gel electrophoresis, which reacted specifically with the antibody. However only one band was observed in non-denaturing gel and also in isoelectric focusing with a pI value of 6.6. This study showed the existence of an unique protein on the plasma membrane surface of normal rat liver cells which disappeared in rat hepatomas induced by chemical carcinogens.

• Parasites, Hosts and Diseases
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• v.29 no.4
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• pp.363-370
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• 1991

인체감염이 다발하는 폐흡충증의 혈청학적 진단에서 항원으로 사용하는 성충추출액은 여러단계의 질환 이행과정을 진단하는 항원으로서 문제가 있다. 이를 해결하려면 먼저 추출액내의 성분단백질의 성상을 파악할 필요가 있다. 이 연구에서는 폐흡충 성충 추출액으로 면역시킨 BALB/c mice의 비장세포와 SP2/0 형질세포종 세포를 세포융합하여 제작한 단세포군항체를 이용하여 친화성크로마토그래피로 폐흡충 성충의 구성단백질의 일부를 순수분리하고 성상을 관찰하였다. 그 결과는 다음과 같다. 1. 세포융합으로 PFCK-21, PFCK-44, PFCK-136, PFCK-189 등 4종류의 단세포군 항체를 얻었다. 그중 PFCK-21과 PFCK44는 17k Da, PFCK-136은 23, 46, 92 kDa 단백질에 반응하였고 PFCK-189는 여러종류의 단백질에 반응하였다. 2. PFCK-44 단세포군항체를 고리로 친화성 크로마토그래피를 실시하여 분리한 성분 단백질은 disc-PAGE상 4번째에 위치하고 분자량이 17 kDa로 알려진 단밸질이었다. 이 단밸질은 17 kDa의 monomer로 판단하였다. 면역조직화학염색을 실시한 결과 이 단밸질은 장관 상피세포에 반응하고 있었다. 3. PFCK-136 단세포군항체로 순수분리한 단밸질은 disc-PAGE상 1번 단밸질(440 kDa)이었으며 환원성 SDS-PAGE에서는 23 kDa 단밸질이었다. 면역조직화학염색으로 이 단세포군항체는 충란내 세포에 강하게 반응하고 있었다.

• Journal of Food Hygiene and Safety
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• v.28 no.3
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• pp.267-271
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• 2013

A survey of aflatoxin $B_1$ and ochratoxin A was conducted on dried red pepper and red pepper powder. Total number of 193 samples were collected from local markets in Incheon. The presence of aflatoxin $B_1$ and ochratoxin A was determined by high performance liquid chromatography (HPLC) with fluorescence detector using immunoaffinity column clean-up. The recovery rate of aflatoxin $B_1$ and ochratoxin A were more than 80% and the limits of quantification were 0.13 ${\mu}g/kg$ for aflatoxin $B_1$ and 0.30 ${\mu}g/kg$ for ochratoxin A. Aflatoxin $B_1$ was detected in 33 samples (17.1%) with a range of 0.14~9.67 ${\mu}g/kg$ and ochratoxin A was detected in 40 samples (20.7%) with a range of 0.31~3.31 ${\mu}g/kg$. These results show that the occurrence of aflatoxin $B_1$ and ochratoxin A in dried red pepper and red pepper powder tested in this study is low compared with the standard in Korea Food Code (10 ${\mu}g/kg$ as aflatoxin $B_1$ and 7 ${\mu}g/kg$ as ochratoxin A).

• Korean Journal of Food Science and Technology
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• v.41 no.3
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• pp.258-264
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• 2009

The principal objective of this study was to estimate the measurement uncertainty associated with determination of deoxynivalenol (DON), a mycotoxin generated by Fusarium strain, in food. In service of this goal, wheat as a food matrix was analyzed via high performance liquid chromatography-ultraviolet (HPLC-UV) detection using an immunoaffinity column for clean-up. The uncertainty sources in the measurement process were identified by sample weight, final volume, and sample concentration in extraction volume with components including standard stock solution, working standard solution, 5 standard solutions, calibration curve, matrix, and instrument. The expanded uncertainty for DON at a concentration of 300 ${\mu}g/kg$ was estimated as 71.62 ${\mu}g/kg$ using a coverage factor of two, which provides a confidence level of approximately 95%. The most influential component in the uncertainty sources was the recovery of the wheat matrix, followed by the calibration curve. These results indicate that all efforts may be directed toward reducing the uncertainties of the recovery of the wheat matrix and the calibration curve to obtain a reliable HPLC-UV method for DON analysis in wheat.

• Parasites, Hosts and Diseases
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• v.28 no.3
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• pp.135-142
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• 1990

The quality improvement of antigen (crude saline extract) of Spirometra maptscni 1)lerocercoid (sparganum) was investigated by protein purificatioll. The crude extract was fractionated by gel filtration through Sephacryl S-300 Superfine. Its third fraction was purified by affinity chromatography using a monoclonal antibody as ligand. When observed by SDS-PAGE, the purified protein was composed of 2 bands of 36 kDa and 29 kDa which were found already as the most sensitive components in the crude extract by immunoblots with patients sera. The quality of the purified antigen was evaluated in comparison with the crude extract by ensyme-linked imnunosorbent assay (ELISA) for the specific (IgG) antibody in sera of human sparganosis, other parasitic and neurologic diseases, and normal control. When the purified antigen was used: the sensitivity was not altered but remained high (96.4%) while the specificity was increased from 86.8% to 96.9%.

• Korean Journal of Pharmacognosy
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• v.48 no.1
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• pp.56-62
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• 2017

The aim of this study was to screen the contamination by ochratoxin A of mycotoxins in various medicinal herbs. We conducted a survey of ochratoxin A in medicinal herb on the retail market in Incheon in 2016. 116 medicinal herb samples were evaluated for the ochratoxin A contamination. They were analyzed for ochratoxin A using immunoaffinity column and high-performance liquid chromatography(HPLC)-fluorescence detection and the positive samples were confirmed using HPLC-tandem mass spectrometry. Ochratoxin A was detected in 4 medicinal herb samples; the concentrations of ochratoxin A were containing between 20.11 and $372.90{\mu}g/kg$. This study shows that in general, this kind of commodity may be contaminated by mycotoxins. Also this contamination is not limited to only aflatoxin of mycotoxins.

• Parasites, Hosts and Diseases
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• v.51 no.5
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• pp.595-597
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• 2013

In December 2011, we reported an autochthonous case of Echinococcus multilocularis infection in a 42-yearold woman in Korea. The diagnosis was based on histopathological findings of the surgically resected liver cyst. In the present study, we evaluated the serological and molecular characteristics of this Korean E. multilocularis case. The patient's serum strongly reacted with affinity-purified native Em18 and recombinant Em18 antigens (specific for E. multilocularis) but negative for recombinant antigen B8/1 (reactive for Echinococcus granulosus). In immunoaffinity chromatography, the serum also strongly reacted with E. multilocularis and only weakly positive for E. granulosus. We determined the whole nucleotide sequence of cox1 (1,608 bp) using the paraffin-embedded cystic tissue which was compared with E. multilocularis isolates from China, Japan, Kazakhstan, Austria, France, and Slovakia. The Korean case showed 99.8-99.9% similarity with isolates from Asia (the highest similarity with an isolate from Sichuan, China), whereas the similarity with European isolates ranged from 99.5 to 99.6%.

• Korean Journal of Food Science and Technology
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• v.44 no.2
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• pp.247-250
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• 2012

Raw milk samples (n=28) obtained from milk tanks in 3 dairy plants of different regions and commercial milks (n=100) were collected from six cities. These samples were analyzed for the level of aflatoxin $M_1$ contamination using immunoaffinity columns and high performance liquid chromatography coupled with fluorescent detectors. Confirmation of aflatoxin $M_1$ ($AFM_1$) identified in positive samples was based on the formation of the hemiacetal derivative ($AFM_{2a}$) after derivatization with trifluroacetic acid. The average concentrations of aflatoxin $M_1$ in the raw milks were 25.1 ng/kg, and those values in commercial milks were 29.8 ng/kg. The highest level of aflatoxin $M_1$ in milk was 72.7 ng/kg. These results showed that the contamination of aflatoxin $M_1$ in milks consumed in the Korea was quite low compared to the standard in Korea Food Code (aflatoxin $M_1$ 500 ng/kg).

• Biomedical Science Letters
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• v.15 no.1
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• pp.37-45
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• 2009

Insect cell cultures have become important tools in the production of biological substances for use in a variety of research, human and veterinary medicine, and pest control applications. These applications often require the introduction of foreign DNA into the cells and have generally used methods originally developed for use with human and other mammalian cell cultures. While these methods can be successfully employed, they are often less efficient with insect cells and frequently involve complex procedures or require specialized equipment. Even when they do work, they may require substantial modification because of differences in the culture medium or growth patterns of insect cells. In this study, We have optimized transfection conditions of Sf9 cell line using insect expression vector pIZT/V5-His which expresses green fluorescent protein effectively. Human stem cell factor (hSCF) is a glycoprotein that plays a key role in hematopoiesis acting both as a positive and negative regulator, often in synergy with other cytokines. It also plays a key role in mast cell development, gametogenesis, and melanogenesis. It can exist in membrane-bound form and in proteolytically released soluble form. As determined by an enzyme-linked immunosorbent assay performed, hSCF level in supernatant averaged 995ng/ml. The human hSCF was partially purified by immunoaffinity chromatography and analyzed with sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting. The results show that the hSCF has N-linked carbohydrate and corresponds to the soluble form, at or about 223 amino acids in length. The findings suggest functional importance for soluble hSCF in cells.

• Journal of Food Hygiene and Safety
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• v.26 no.3
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• pp.214-221
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• 2011

Deoxynivalenol (DON) and zearalenone (ZEN) are mainly contaminated mycotoxins in feeds. The study was carried out to analyze and survey the contamination of DON and ZEN in one hundred thirteen samples of feeds. After cleaning all samples with immunoaffinity column, the mycotoxins were analysed by using high performance liquid chromatography/fluorescence with diode array detector (HPLC/FLD with DAD). The average recoveries of DON were 88.76 and 95.40% at the levels of 200 and 1,000 ${\mu}g/kg$ and 87.09 and 98.40% of ZEN were recovered at the levels of 100 and 500 ${\mu}g/kg$, respectively. The limit of detection (LOD) were 6.0 and 3.0 ${\mu}g/kg$ for DON and ZEN, respectively. The average concentrations of DON were 372.1, 324.0 and 990.9 ${\mu}g/kg$ in chicken, pig and cattle feed, respectively. Those of ZEN were 76.1, 43.7 and 196.2 ${\mu}g/kg$ for them, individually.