Morinaga Institute of Biological Science Inc.

Kanazawa-shi, Japan

Morinaga Institute of Biological Science Inc.

Kanazawa-shi, Japan

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Oyama Y.,Morinaga Institute of Biological Science Inc. | Osaki T.,Kanagawa Academy Of Science And Technology | Kamiya K.,Kanagawa Academy Of Science And Technology | Sawai M.,Morinaga Institute of Biological Science Inc. | And 2 more authors.
Sensors and Actuators, B: Chemical | Year: 2017

We developed a highly sensitive point-of-care testing (POCT) chip using an antigen-antibody complex reaction for the early diagnosis of infectious disease. The central concept of the chip was to balance the sensitivity enhancement with appropriate safety measures for infectious risk during POCT. The chip consisted of a sheet of glass fiber sealed in a polymethylmethacrylate microfluidic channel. Antibody-immobilized microbeads were accumulated in a transparent location in the channel that served as the test line, trapping the target antigen bound to fluorescently labeled antibodies and allowing diagnosis by a portable fluorescence scanner. In this work, we applied a superabsorbent polymer to drive a stable and continuous fluidic flow for both the sample and a rinsing solution without an external power supply. The generated flow enabled thorough bound/free separation of the antigen-antibody interactions and significantly improved the signal-to-noise ratio and the reproducibility. Moreover, the polymer had the advantage of retaining the potentially infectious sample within the chip, contributing to its safety for practical use. An influenza test using a virus protein exhibited a sensitivity enhancement of more than a thousand-fold compared with commercial immunochromatographic test strips. © 2016 Elsevier B.V.

Oyama Y.,Hamamatsu Photonics K K | Oyama Y.,Morinaga Institute of Biological Science Inc. | Osaki T.,Kanagawa Academy Of Science And Technology | Kamiya K.,Kanagawa Academy Of Science And Technology | And 5 more authors.
Lab on a Chip - Miniaturisation for Chemistry and Biology | Year: 2012

We have developed a quantitative immunoassay chip targeting point-of-care testing. To implement a lateral flow immunoassay, a glass fiber sheet was chosen as the material for the microfluidic channel in which the negative charge on the fiber surfaces efficiently generates the electroosmotic flow (EOF). The EOF, in turn, allows controllable bound/free separation of antigen/antibody interactions on the chip and enables precise determination of the antigen concentration. In addition, the defined size of the porous matrix was suitable for the filtration of undesired large particles. We confirmed the linear relationship between the concentration of analyte and the resulting fluorescence intensity from the immunoassay of two model analytes, C-reactive protein (CRP) and insulin, demonstrating that analyte concentration was quantitatively determined within the developed chip in 20 min. The limits of detection were 8.5 ng mL-1 and 17 ng mL-1 for CRP and insulin, respectively. © 2012 The Royal Society of Chemistry.

Waisarayutt C.,Kasetsart University | Surojanametakul V.,Kasetsart University | Kaewpradub S.,Kasetsart University | Shoji M.,Morinaga Institute of Biological Science Inc. | And 2 more authors.
Food Control | Year: 2014

The understanding and implementation of food allergen management among HACCP-certified Thai food companies were surveyed during 2008-2009 by questionnaires and direct interviews with quality control managers of the companies. Forty of 72 respondents answered that they implemented a food allergen control program as part of existing product quality control and safety management. The awareness and understanding of food allergen management depended on the company's dominance in the market place as well as experience in food quality control and safety management. Although Thailand has no food allergen labeling legislation, the respondents expected that food allergen labeling legislation will soon be adopted in Thailand. Earlier implementation of labeling regulations has been driven by adherence to WTO (Codex) rules. The results of this survey indicated the substantial effectiveness of the present allergen control programs of Thai food manufacturers, and also their potential capability of food allergen management for domestic products at a level equal to that for export products. © 2014 Elsevier Ltd.

Surojanametakul V.,Kasetsart University | Khaiprapai P.,Kasetsart University | Jithan P.,Kasetsart University | Varanyanond W.,Kasetsart University | And 3 more authors.
Food Control | Year: 2012

This study investigates the presence of undeclared allergens - namely milk, egg, wheat and peanut - in commercial processed food products in Thailand. Out of 142 commercial products, 55 positive cases were found (by quantitative ELISA method) to contain an undeclared allergen greater than 10. ppm. Among all positive products, undeclared milk appeared the most frequently (21 cases), followed by egg and wheat with similar frequency (17 cases), while peanut was rarely found. Milk- or egg-positive products were further confirmed by the presence of the milk protein, casein, or the egg protein, ovalbumin, by Western blot test. Our results should help to increase the awareness among Thai food manufacturers of the need for more careful management of allergenic food ingredients, and to encourage the labeling of allergen information for allergic consumers, thus reducing the health hazard from food allergy. © 2011 Elsevier Ltd.

Kohno K.,The University of Shimane | Matsuo H.,Hiroshima University | Takahashi H.,The University of Shimane | Niihara H.,The University of Shimane | And 6 more authors.
Allergology International | Year: 2013

Background: Challenge testing with wheat plus exercise and/or aspirin is a gold standard for the diagnosis of wheat-dependent exercise-induced anaphylaxis (WDEIA); however, the test may often yield false-negative results. Our previous study suggested that an increase in serum wheat gliadin levels is required to induce allergic symptoms in patients with WDEIA. Based on this knowledge, we sought to extract the patients with false negative results in the challenge tests of WDEIA. Methods: Thirty-six patients with suspected WDEIA were enrolled. First, group categorizations-Group I, challenge tests were positive; Group II, challenge tests were negative and serum gliadin were undetectable; Group III, challenge tests were negative and serum gliadin were detectable-were given according to the results of wheat plus exercise and/or aspirin challenge testing and serum gliadin levels. Second, diagnoses were made using retests and/or dietary management in Group II and III. Results: Positive results for wheat plus exercise and/or aspirin challenge tests gave a diagnosis of definite WDEIA in 17 of 36 patients (Group I). Of the remaining 19 challenge negative patients, serum gliadin was undetectable in ten patients (Group II). Of the ten patients (Group II), three of them were diagnosed as definite WDEIA by retesting and six of them were diagnosed as probable WDEIA using a wheat elimination diet, whereas one patient was non-WDEIA. In the rest of the nine challenge negative patients, serum gliadin was detectable (Group III). No allergic episodes with a normal diet provided a diagnosis of non-WDEIA in seven of the nine patients, whereas the remaining two patients were probable WDEIA or had another food allergy because of repeated episodes. Conclusions: Our study revealed that serum gliadin monitoring during challenge testing is useful. © 2013 Japanese Society of Allergology.

Sakai S.,Japan National Institute of Health Sciences | Adachi R.,Morinaga Institute of Biological Science Inc. | Akiyama H.,Japan National Institute of Health Sciences | Teshima R.,Japan National Institute of Health Sciences | And 3 more authors.
Journal of AOAC International | Year: 2010

Because food allergens from tree nuts, including walnuts, are a frequent cause of adverse food reactions for allergic patients, the labeling of foods containing ingredients derived from tree nuts is required in numerous countries. According to Japanese regulations, the labeling of food products containing walnuts is recommended. To ensure proper labeling, a novel sandwich ELISA kit for the determination of walnut protein in processed foods (Walnut Protein [2S-Albumin] Kit; Morinaga Institute of Biological Science, Inc.; "walnut kit") has been developed. We prepared seven types of incurred samples (model processed foods: biscuits, bread, sponge cake, orange juice, jelly, chicken meatballs, and rice gruel) containing 10 mg walnut soluble protein/g of food for use in interlaboratory evaluations of the walnut kit. The walnut kit displayed sufficient reproducibility relative standard deviations (interlaboratory precision: 5.8-9.9% RSDR) and a high level of recovery (81-119%) for all the incurred samples. All the repeatability relative standard deviation (RSDr) values for the incurred samples that were examined were less than 6.0%. The results of this interlaboratory evaluation suggested that the walnut kit could be used as a precise and reliable tool for determination of walnut protein in processed foods.

Kitao N.,Asahikawa University | Fukui D.,Asahikawa Municipal Asahiyama Zoological Park and Wildlife Conservation Center | Shibata H.,Morinaga Institute of Biological Science Inc. | Saito M.,Tenshi College | And 2 more authors.
Journal of Experimental Zoology Part A: Ecological Genetics and Physiology | Year: 2011

Leptin is an adipocyte-derived peptide hormone that acts on the brain and regulates food intake and energy balance. Several previous reports have suggested that overwintering raccoon dogs Nyctereutes procyonoides are able to control their adiposity efficiently, but the contribution of leptin to weight regulation in these animals remains unclear. To study the seasonality of overwintering raccoon dogs as well as the effects of fasting on them, serum leptin levels were investigated using a newly established canine leptin-specific enzyme-linked immunosorbent assay (ELISA) kit. Of the nine animals studied, five were fed and four were fasted (deprived of food for 2 months in winter). Blood samples and body fat weights were monitored once a month throughout the experimental period (July 2007-March 2008). Leptin concentrations obtained by ELISA were significantly higher than and had a positive correlation with those obtained by previously used multispecies radioimmunoassay (RIA) kits. Moreover, ELISA showed a clearer correlation between the body fat weight and leptin levels compared with RIA, suggesting the efficacy of canine leptin-specific ELISA kit for leptin estimation in raccoon dogs. Autumnal fattening was observed in both groups of animals, but the wintertime loss of adipose tissue was more obvious in the fasted group. Serum leptin concentrations determined by ELISA showed seasonal changes without significant differences between the fed and fasted animals. Therefore, high levels of leptin may be responsible for the suppression of feeding behavior in raccoon dogs before winter. Copyright © 2010 Wiley-Liss, Inc., A Wiley Company.

PubMed | Morinaga Institute of Biological Science Inc.
Type: Journal Article | Journal: Cytotechnology | Year: 2012

Potassium or sodium phosphate was found to stimulate the production of human monoclonal antibody by human-human hybridoma HB4C5. The addition of 15 mM Na-phosphate (pH 7.4) into serum-free culture medium increased the antibody production up to 4-fold, when seeded at cell density of 110(5) cells/ml in dishes. At the higher cell density of 510(5) cells/ml, K-phosphate was more effective than Na-phosphate, at the same concentration. In large-scale continuous culture, the addition of 10 mM Na-phosphate into serum-free culture medium stimulated antibody production by HB4C5 cells 6-fold.

PubMed | Morinaga Institute of Biological Science Inc.
Type: Journal Article | Journal: The Journal of veterinary medical science | Year: 2016

A sensitive and reproducible enzyme-linked immunosorbent assay (ELISA) using two monoclonal antibodies directed against a synthetic peptide with an amino-acid sequence related to the C-terminus of bovine myoglobin and the whole molecule of sodium dodecyl sulphate (SDS)-denatured bovine myoglobin was adapted for detecting bovine myoglobin in contaminated feeds. The ELISA employed bovine meat extract of a known myoglobin concentration as a calibration standard and had an limit of detection (LOD) of 3.54 ng/ml and an limit of quantification (LOQ) of 11.0 ng/ml corresponding to 0.022% and 0.067% (wt/wt) bovine meat-and-bone-meal (MBM) mixed in 20-fold-diluted feed extracts, respectively. A cut-off threshold of 20.6 ng/ml bovine myoglobin was set to simplify ELISA and facilitate quick assessment of test results without a tedious calibration process. The ELISA was able to detect bovine MBM in artificially prepared model feeds, mixed botanical feeds, mixed botanical feeds with skimmed milk, fish meal, pork meal and pork/chicken meal at 0.1% (wt/wt). It was also able to detect sheep MBM in test feeds, but showed no reactivity to swine MBM, chicken MBM, skimmed milk or gelatine of bovine origin. The advantages of this method are the quick and easy extraction protocol of proteins from test feeds, using 100 mM sodium sulphide and 0.6% sodium dodecyl sulphate in the extraction solution and the effective detection of bovine and sheep MBM at 0.1% (wt/wt).

PubMed | Morinaga Institute of Biological Science Inc. and Carbuncle BioScienTech LLC
Type: Journal Article | Journal: Journal of agricultural and food chemistry | Year: 2016

The presence of dieldrin and heptachlor residues in cucurbitaceous crops at concentrations exceeding the limits set by the Japanese Food Sanitation Law constitutes a serious problem. To prevent accumulation of these residues in cucurbitaceous crops, development of high-throughput analysis methods for the detection of contaminants in the soil before cultivation is required. This study aimed to develop a model immunoassay using new monoclonal antibodies (MAbs) to quantitatively determine dieldrin and heptachlor contents in their mixtures. Three distinctive MAbs were obtained from mice immunized with the respective immunogens. MAb DrA-04 showed high reactivity toward dieldrin with ca. 20% cross-reactivity toward heptachlors. MAb DrC-02 displayed a similar reactivity toward dieldrin and heptachlors. The specificity and sensitivity of MAbs DrA-04 and DrC-02 were largely unaffected by the composition ratio of heptachlors in a mixture. Six standard mixtures with different dieldrin and heptachlor contents were prepared. Concentrations of dieldrin and heptachlors in standard mixtures, calculated on the basis of an immunoassay with MAbs DrA-04 and DrC-02, were 88.1-125 and 96.2-115% of the theoretical values, respectively, revealing excellent sensitivity and specificity of this assay. The developed method paves the way for a facile and rapid quantitative determination of chlorinated cyclodiene pesticides in soil.

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