• Korean Journal of Clinical Laboratory Science
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• v.42 no.3
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• pp.116-124
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• 2010

This study was aimed to clerify the cytotoxicity of some plant extracts such as Hosta longissima HONDA (HL), Hemerocallis fulva var. Kwanso REGL (HFVK), Hemerocallis fulva L (HF), Macrocapium officinale NAKAI (MO) and Mentha canadensis var. piperascens HARA (MCVP), the cultured NIH3T3 fibroblasts were treated with 25, 50, 100, 150 and $200{\mu}g/mL$ of five kinds of plant extracts for 48 hours, respectively. The cytotoxicity of plant extracts was measured by MTT and NR assays for the cell viability, and XTT assay for the cell adhesion activity. In this study, HL, MO and FHVK extracts showed the range of midtoxic-non toxic by the criteria of chemical cytotoxicity. While, the HF and MCVP extracts showed midtoxic. In the extract cytotoxicity, HL, MO and FHVK extracts showed non-toxic by the criteria of extract cytotoxicity. While, HF extract was determined as lower-toxic. In the responsive sensitivity of each plant extract on colorimetric assays, HF extract was sensitive to mitochondrial enzyme by MTT assay, lysosomal enzyme by NR assay and mitochondrial nucleus by XTT assay. While, MCVP extract was sensitive to mitochondrial enzyme by MTT assay and lysosomal enzyme by NR assay than other assays. While, HL, HFVK and MO extracts were most sensitive to NR assay. Cell culture is one of useful materials in the screening of cytotoxic and recovary effect on the putative chemical agents or plant extract. And also, colorimetric assay is regarded as very useful tools for quantitative measurement of cytotoxic effect on plant extracts in vitro.

• Journal of Food Hygiene and Safety
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• v.6 no.3
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• pp.111-117
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• 1991

We examined to develop the enzyme linked immunosorbent assay (ELISA) for determination of zearalenone in animal feeds. Zearalenone was first converted to 6'-(carboxymethyl) zearalenone oxime(zearalenone oxime) to get a coupling site and then conjugated to bovine serum albumin(BSA) for use as immunogen and to horseradish peroxidase(HRP) for use as enzyme marker. Antibody against zearalenone was obtained after 11 weeks of immunization of rabbit with zearalenone oxime-BSA. Cross reactivity of the antibody with ${\alpha}-zearalanol,\;{\beta}-zearalenol,\;{\alpha}-zearalanol\;and\;{\beta}-zearalanol$ were 168, 46, 26 and 20% respectiviely. A simple procedure was devised for the screening of zearalenone in feeds using ELISA. Feeds samples(5g) were extracted by blending with 25 ml of methanol-phospate butTered saline-dimethylformate(70 : 29 : 1) and the extract was filtered and aqueous filterate analyzed. It took only 1 hours to do whole procedure for the analysis of zearalenone in feeds by the direct competitive ELISA, and detectable limit was 1-100 ppb. Using this procedure, only 4 of 24 feed samples showed positive results with 3.93-7.43 ppb levels.

• Food Science and Biotechnology
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• v.15 no.6
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• pp.990-992
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• 2006

In a previous study, we obtained polyclonal antibodies against the organophosphorus insecticide fenitrothion and developed an enzyme-linked immunosorbent assay (ELISA) for this pesticide. Using these antibodies and an enzyme tracer, a direct competitive ELISA method specific for fenitrothion using a dipstick format was developed. Dipstick ELISA using antibodies to fenitrothion immobilized on an Immunodyne membrane allowed the quick visual detection of fenitrothion at concentrations above $10\;{\mu}g/L$. The $IC_{50}$ value of dipstick ELISA using reflectance detection was $27\;{\mu}g/L$ with a detection limit of $2\;{\mu}g/L$. The recovery of fenitrothion from spiked lettuce and rice samples using the dipstick ELISA ranged from 87-107%.

• Bulletin of the Korean Chemical Society
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• v.17 no.11
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• pp.1018-1022
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• 1996

Adenosine deaminase (ADA) has been utilized as the label in devising a potentiometric homogeneous assay for riboflavin and riboflavin binding protein (RBP). The proposed homogeneous assay method employs an ADA-biotin conjugate as the signal generator and an avidin-riboflavin conjugate as the signal modulator in the solution phase. The catalytic activity of the ADA-biotin conjugate is inhibited in the presence of an excess amount of the avidin-riboflavin conjugate, and the observed inhibition is reversed in an amount proportional to the concentration of RBP added. When the analyte riboflavin is added to this mixture of ADA-biotin, avidin-riboflavin and RBP, the activity of the enzyme conjugate is re-inhibited in an amount proportional to the concentration of riboflavin. Since the enzyme label used in this system is ADA, an ammonia-producing enzyme, a potentiometric rather than photometric detection scheme is used to monitor the enzymatic activity in the assay.

• Microbiology and Biotechnology Letters
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• v.17 no.4
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• pp.365-369
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• 1989

Thermal inactivation of Tyichoderma viride cellobiohydrolase was investigated by immunoassay and residual enzyme assay such as carboxymethyl cellulase (CMCase) and filter paper degradation activity (FPase). Arrhenius plots of cellobiohydrolase were appeared as straight line. The Z-values of cellobiohydrolase calculated by CMCase, FPase and immunoassay were 5.2$^{\circ}C$, 6.4$^{\circ}C$ and 5.8$^{\circ}C$, respectively. The thermodynamic parameters obtained from FPase were better agreement with those of immunoassay than CMCase assay.

• BMB Reports
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• v.30 no.4
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• pp.258-261
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• 1997

A simple quantitative assay method for ribonuclease activity has been developed. This method is based on the decrease of fluorescence intensity emitted by the ethidium bromide bound to RNA due to the degradation of RNA by ribonuclease. The substrate RNA was reacted with ribonuclease A and the fluorescence intensity was measured after the addition of ethidium bromide. The intensity difference was calculated using a blank reaction mixture containing no RNase. Whole cellular RNA substrate produced a significant error and was not suitable for this assay method possibly because of local microheterogeniety caused by high molecular weight rRNA. but satisfying results were obtained with tRNA substrate. The intensity difference increased linearly by raising enzyme concentration up to $2{\times}10^{-4}$ Kunitz Units of ribonuclease A. More refined and reliable results were obtained by use of initial reaction velocities which were calculated from the plots of intensity difference vs time. A linear relationship between initial velocities and enzyme concentrations was observed up to 0.01 Kunitz Units of enzyme.

• Bulletin of the Korean Chemical Society
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• v.23 no.4
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• pp.605-609
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• 2002

A competitive enzyme-linked immunosorbent assay (ELISA) was developed for the quantitative detection of organophosphorus insecticide cyanophos. An analogue (hapten) of cyanophos was synthesized and was coupled to BSA to produce polyclonal antibodi es from rabbits. The antisera were screened against another hapten coupled to ovalbumin (OVA). Using the sera of highest specificity, an antigen-coated ELISA was developed, which showed an I50 of 310 ng/mL with the detection limit of 20 ng/mL. The antibodies showed negligible cross-reactivities with other organophosphorus pesticides except for parathion-methyl, which makes the assay suitable for the selective detection of cyanophos.

• Journal of Pharmaceutical Investigation
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• v.33 no.4
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• pp.273-279
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• 2003

Pancreatin is a enzyme mixture breaking down carbohydrates, proteins and lipids. Most pancreatin used in Korea is imported from foreign countries. However, guideline of each country for pancreatin produced from each country is different. Therefore, guideline for pancreatin imported from several countries, such as Europe, Japan and America, it is standardized to control its quality. Assay of enzyme activity for pancreatin in KP is similar to tat in JP, but it is significantly different from those in FP ad in USP. We measured pancreatin digestive activities of 17 commercial products. Activity assay of digestive enzymes, starch- and lipid-digestive enzymes, for pancreatin by KP method (including JP) was difficult compared to those by FIP ad USP methods. Particularly, activity assays of starch- and lipid-digestive enzymes by KP method were mistakable, ad varied in diluted samples than those by FIP. However, activity assay of protein-digestive enzyme by KP method was similar to that by FIP. Starch-digestive enzyme activities of 17 commercial pancreatins by KP method were lower 0.079-fold compared to those by FIP method. Their protein-digestive enzyme activities by KP method were higher 75.7-fold than those by FIP method. Their lipid-digestive enzyme activities by KP method were lower 0.234-fold compared to those by FIP method.

• 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.

• Korean Journal of Microbiology
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• v.15 no.4
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• pp.145-153
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• 1977

Penicillin amidase (EC 3.5.1.11) was produced by a mutant strain of Bacillius megaterium ATCC 14945. Hydroxylamine assay method for the determination of 6-APT was modified by using "HCl addition techniques" in order to simplify the time consuming orginal assay method without sacrifice of accuracy. Using the new mutant strain, the effects of fermentation conditions on enzyme production were studied.e studied.