Evaluation of Performance of a Commercial Monoclonal Antibody–Based Fenitrothion Immunoassay and Application to Residual Analysis in Fruit Samples

2006 ◽  
Vol 69 (1) ◽  
pp. 191-198 ◽  
Author(s):  
EIKI WATANABE ◽  
KOJI BABA ◽  
HEESOO EUN ◽  
TOMOHITO ARAO ◽  
YASUO ISHII ◽  
...  

The performance of a commercially available enzyme-linked immunosorbent assay (ELISA) kit containing highly sensitive monoclonal antibodies against fenitrothion was assessed. The experimentally estimated dynamic range (0.087 to 2 ng/g) agreed with that established by the kit manufacturer (0.075 to 1 ng/g). The linearity of the standard curve produced for the kit-assembled standard solutions (slope = −0.3829) agreed with that of the curve produced for the self-made standard solutions (slope =−0.3619). The sensitivity (I50 value) and the limit of detection for the kit were 0.23 and 0.033 ng/g, respectively. Selectivity of the ELISA indicates that the monoclonal antibody can readily distinguish the target pesticide from other structurally related analogs and some metabolites (oxon forms), with the exception of ethyl O-(p-nitrophenyl) phenyl phosphonothionate (EPN), parathion-methyl, and parathion. Methanol was the best organic solvent for the kit, with optimal sensitivity observed at a final concentration in the well of 10% (vol/vol) or less. Matrix interferences were minimized by direct dilution with water (60-fold) of the methanolic extracts from apple and peach samples. To extract fenitrothion from these two agricultural products as simply and rapidly as possible, three extraction methods were used. The extraction method that involved shaking by hand for 3 min was the best among the three methods. High recovery percentages (116.6% for apple and 110.8% for peach) were obtained. Validation of the ELISA method was carried out using the gas chromatography–mass spectrometry method, resulting in high recovery and close correlation of results (r > 0.95). These findings strongly suggest that the ELISA kit may be routinely employed for on-site fenitrothion screening of fruit samples.

Chemosensors ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 159
Author(s):  
Satit Rodphukdeekul ◽  
Miyuki Tabata ◽  
Chindanai Ratanaporncharoen ◽  
Yasuo Takeuchi ◽  
Pakpum Somboon ◽  
...  

Periodontal disease is an inflammatory disorder that is triggered by bacterial plaque and causes the destruction of the tooth-supporting tissues leading to tooth loss. Several bacteria species, including Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans, are considered to be associated with severe periodontal conditions. In this study, we demonstrated a quartz crystal microbalance (QCM) immunoassay for quantitative assessment of the periodontal bacteria, A. actinomycetemcomitans. An immunosensor was constructed using a self-assembled monolayer of 11-mercaptoundecanoic acid (11-MUA) on the gold surface of a QCM chip. The 11-MUA layer was evaluated using a cyclic voltammetry technique to determine its mass and packing density. Next, a monoclonal antibody was covalently linked to 11-MUA using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide to act as the biorecognition element. The specificity of the monoclonal antibody was confirmed by an enzyme-linked immunosorbent assay. A calibration curve, for the relationship between the frequency shifts and number of bacteria, was used to calculate the number of A. actinomycetemcomitans bacteria in a test sample. Based on a regression equation, the lower detection limit was 800 cells, with a dynamic range up to 2.32 × 106 cells. Thus, the QCM biosensor in this study provides a sensitive and label-free method for quantitative analysis of periodontal bacteria. The method can be used in various biosensing assays for practical application and routine detection of periodontitis pathogens.


1994 ◽  
Vol 57 (2) ◽  
pp. 169-172 ◽  
Author(s):  
JAMES J. PESTKA ◽  
JUAN I. AZCONA-OLIVERA ◽  
RONALD D. PLATTNER ◽  
FIORENZA MINERVINI ◽  
M. BRUNO DOKO ◽  
...  

Seventy-one (71) food samples were analyzed for the mycotoxin fumonisin by a monoclonal antibody based competitive enzyme-linked immunosorbent assay (ELISA). Fumonisins were detected primarily in corn-based products with 7/12, 2/2 and 1/3 and 1/7 yellow cornmeal, blue cornmeal, corn muffin mix, and mixed grain cereal samples yielding positive results, respectively. When the positive samples and randomly selected negative samples were assessed by other methods, correlations (r values) between ELISA and gas chromatography-mass spectrometry (GC-MS), ELISA and high-pressure liquid chromatography (HPLC) and GC-MS and HPLC were 0.478 (p < 0.05), 0.512 (p < 0.05), and 0.946 (p < 0.01), respectively. The results suggested that although the immunoassay could be used for screening of fumonisin in food samples, higher estimates were attained by ELISA than by the other two methods particularly in the more contaminated samples. These observations may result from differences in sample preparation among the methods or because of the presence of structurally related compounds in extracts that are detectable by ELISA but not the other two methods.


Planta Medica ◽  
2018 ◽  
Vol 84 (14) ◽  
pp. 1038-1044 ◽  
Author(s):  
Benyakan Pongkitwitoon ◽  
Seiichi Sakamoto ◽  
Rika Nagamitsu ◽  
Waraporn Putalun ◽  
Hiroyuki Tanaka ◽  
...  

AbstractHomoharringtonine (HHT), also known as omacetaxine, is a natural compound found in the genus Cephalotaxus and is a promising pharmaceutical drug used for the treatment of chronic or accelerated phase chronic myeloid leukemia. As a tool for the quantitative determination of HHT, a specific monoclonal antibody against HHT (MAb 6A1) was generated by conjugates prepared via sodium periodate-mediated oxidation. The developed indirect competitive enzyme-linked immunosorbent assay (icELISA) using MAb 6A1 was found to be highly specific and sensitive with a limit of detection for HHT of 48.8 ng/mL. Validation assays to evaluate precision and accuracy of the method were conducted by the use of intra- and inter-assay analysis, recovery test, and comparison analysis between the amounts of HHT determined by ELISA and high-performance liquid chromatography. These results revealed that the established icELISA using MAb 6A1 is specific, sensitive, and reliable enough to be applied to the qualitative analysis for HHT. Furthermore, the results of this study support the usefulness of sodium periodate as a reagent for the conjugation between Cephalotaxus alkaloids and proteins for producing specific antibodies.


Planta Medica ◽  
2017 ◽  
Vol 83 (10) ◽  
pp. 855-861 ◽  
Author(s):  
Tharita Kitisripanya ◽  
Supaluk Krittanai ◽  
Orapin Udomsin ◽  
Kamonthip Jutathis ◽  
Jukrapun Komaikul ◽  
...  

AbstractMiroestrol is a chromene with potent estrogenic activity present in Pueraria candollei, commonly known as White Kwao Krua. Although this compound is only present in low amounts in the plant, it plays an important role in the estrogenic action of P. candollei products. As a tool for further studies about the efficacy and safety of P. candollei as a phytoestrogenic supplement, we generated a novel monoclonal antibody against miroestrol. This anti-miroestrol monoclonal antibody was used to develop an immunoassay for the determination of miroestrol content, which can be used for quality control purposes of P. candollei. The developed ELISA against miroestrol has a calibration range of 10–780 ng/mL miroestrol, a limit of detection of 3.5 ng/mL, and a limit of quantitation of 12.2 ng/mL. According to the validation analysis, the established ELISA is precise, accurate, specific, and sensitive for miroestrol detection in plants. Furthermore, the anti-miroestrol monoclonal antibody was used to prepare an immunoaffinity column for the isolation of miroestrol from the tuberous root of P. candollei. The column provides a simple procedure for miroestrol isolation, with a capacity of 3.91 µg of miroestrol per 1 mL of immunogel.


Foods ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2398
Author(s):  
Xiya Zhang ◽  
Mingyue Ding ◽  
Chensi Zhang ◽  
Yexuan Mao ◽  
Youyi Wang ◽  
...  

The consumption of shellfish contaminated with brevetoxins, a family of ladder-frame polyether toxins formed during blooms of the marine dinoflagellate Karenia brevis, can cause neurotoxic poisoning, leading to gastroenteritis and neurotoxic effects. To rapidly monitor brevetoxin levels in oysters, we generated a broad-spectrum antibody against brevetoxin 2 (PbTx-2), 1 (PbTx-1), and 3 (PbTx-3) and developed a rapid indirect competitive enzyme-linked immunosorbent assay (icELISA). PbTx-2 was reacted with carboxymethoxylamine hemihydrochloride (CMO) to generate a PbTx-2-CMO hapten and reacted with succinic anhydride (HS) to generate the PbTx-2-HS hapten. These haptens were conjugated to keyhole limpet hemocyanin (KLH) and bovine serum albumin (BSA) to prepare immunogen and coating antigen reagents, respectively, using the active ester method. After immunization and cell fusion, a broad-spectrum monoclonal antibody (mAb) termed mAb 1D3 was prepared. The 50% inhibitory concentration (IC50) values of the icELISA for PbTx-2, PbTx-1, and PbTx-3 were 60.71, 52.61, and 51.83 μg/kg, respectively. Based on the broad-spectrum mAb 1D3, an icELISA was developed to determine brevetoxin levels. Using this approach, the limit of detection (LOD) for brevetoxin was 124.22 μg/kg and recoveries ranged between 89.08% and 115.00%, with a coefficient of variation below 4.25% in oyster samples. These results suggest that our icELISA is a useful tool for the rapid monitoring of brevetoxins in oyster samples.


2020 ◽  
Author(s):  
Yukiyo Kasahara ◽  
Satoko Osuka ◽  
Bayasula Bayasula ◽  
Natsuki Nakanishi ◽  
Tomohiko Murase ◽  
...  

Abstract Background: Patients with primary ovarian insufficiency (POI) present with follicle growth occasionally, however, it is difficult to predict the exact cycles with follicle growth. Serum anti-Müllerian hormone (AMH), a useful marker for ovarian reserve, is produced in early-stage follicles. Therefore, AMH levels should reflect the existence of small follicles which are difficult to detect using ultrasonography and may be useful for predicting follicle growth in patients with POI. Methods: Using an ultrasensitive enzyme-linked immunosorbent assay (ELISA) kit, we found very low serum AMH levels of patients with POI; we further assessed the follicle growth of each patient and their cycles to clarify the usefulness of measuring serum AMH levels for predicting the follicle growth in patients with POI. Results: A total of 91 cycles of 19 patients with POI were analyzed in this study. Five patients presented with positive serum AMH levels during the observational periods and all five experienced follicle growth. Only two of the 14 patients with negative serum AMH levels had follicle growth. Serum AMH and follicle-stimulating hormone (FSH) levels in cycles with follicle growth were significantly higher than in cycles without follicle growth. The median serum AMH level (2.77 pg/mL; 25th, 75th percentiles: 0.0, 9.64) in cycles with follicle growth were lower than the lower limit of detection of conventional AMH ELISA kits. The positive predictive value of positive serum AMH levels for follicle growth was higher than that of FSH (<10 mIU/mL).Conclusions: Measuring very low levels of serum AMH using picoAMH assays is useful for the prediction of follicle growth in patients with POI.


2021 ◽  
Vol 21 (10) ◽  
pp. 5036-5043
Author(s):  
Yan Qiao ◽  
Qing-Yun Cai

In this study, we developed a monoclonal antibody against 2,3’,4,5’,6-pentabromodiphenylether (BDE-121) using a synthesized hapten, and established an indirect competitive enzyme-linked immunosorbent assay (IC-ELISA), using gold nanoparticles, to amplify the signal. The monoclonal antibody showed high specificity, with a half inhibitory concentration (IC50) value of 2.78 ng/mL, towards BDE-121. The developed IC-ELISA exhibited high sensitivity and stability as well as good recovery. The intra-assay deviation is below 6.8% and the inter-assay deviations range from 6.5% to 8.7%. The assay of the actual samples was found to be consistent with those of gas chromatography/mass spectrometry (GC/MS).


1997 ◽  
Vol 78 (04) ◽  
pp. 1262-1267 ◽  
Author(s):  
Claudia C Folman ◽  
Albert E G K von dem Borne ◽  
Irma H J A M Rensink ◽  
Winald Gerritsen ◽  
C Ellen van der Schoot ◽  
...  

SummaryIn this report a sensitive enzyme-linked immunosorbent assay (ELISA) for the measurement of plasma thrombopoietin (Tpo) is described that is solely based on monoclonal antibodies (MoAbs).The assay has an intra and inter-assay variance of 5-7% and 7-13%, respectively. Native and recombinant human Tpo (rhTpo) were recognized equally well, no cross reactivity with other cytokines was found and rhTpo added to plasma and serum was completely recovered. With the ELISA, Tpo concentrations in EDTA-anticoagulated plasma of all controls (n = 193) could be determined, since the limit of detection (2 ± 0.8 A.U./ml, mean ± sd) was lower than the concentration found in controls (11 ± 8 A.U./ml, mean ± sd; 2.5th-97.5th percentile: 4-32 A.U./ml). Tpo levels in serum were on average 3.4 times higher than in plasma.We showed in vivo that Tpo is bound by platelets, as in thrombocytopenic patients (n = 5) a platelet transfusion immediately led to a drop in plasma Tpo level, whereas in patients receiving chemotherapy the induced thrombocytopenia was followed by a rise in plasma Tpo levels.In summary, these results indicate that this ELISA is a reliable tool for Tpo measurements and is applicable for large scale studies.


1997 ◽  
Vol 60 (8) ◽  
pp. 973-977 ◽  
Author(s):  
ANA I. HAZA ◽  
PALOMA MORALES ◽  
ROSARIO MARTÍIN ◽  
TERESA GARCÍIA ◽  
GONZALO ANGUITA ◽  
...  

A stable hybridoma cell line (B2B) has been produced that secretes a monoclonal antibody (MAb) specific for goat's milk αS2-casein. The MAb B2B was used in two enzyme-linked immunosorbent assay (ELISA) formats for the detection and quantification of the presence of goat's milk in ewe's milk. In the indirect ELISA format the limit of detection was 0.5 to 15% (vol/vol) substitution of goat's milk for ewe's milk. Afterwards, a competitive indirect ELISA was successfully developed for the detection of 0.25 to 15% (vol/vol) of goat's milk in ewe's milk. This competitive indirect ELISA is a very sensitive assay; it can be performed in less than 5 h and is not influenced by the heat treatment of milk.


Toxins ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 6 ◽  
Author(s):  
Ming Li ◽  
Mingna Sun ◽  
Xia Hong ◽  
Jinsheng Duan ◽  
Daolin Du

A total of 328 agricultural product samples highly suspected to be contaminated, from flour companies, feed companies, and livestock farms throughout China, were surveyed for deoxynivalenol (DON) contamination using a self-assembly enzyme-linked immunosorbent assay (ELISA) kit. An ELISA kit for DON was developed with a 4.9 ng mL−1 limit of detection (LOD) in working buffer and a 200 ng g−1 LOD in authentic samples. The DON contamination detection rate was 88.7%, concentrations ranged from 200.9 to 6480.6 ng g−1, and the highest DON contamination was found in distillers’ dried grains with solubles with an average of 3204.5 ng g−1. Wheat bran and wheat were found to be the most commonly contaminated samples, and the corn meal samples had the lowest average DON level. This ELISA kit is a powerful alternative method for the rapid, sensitive, specific, accurate, and high-throughput determination of DON and can meet the maximum requirement levels. This survey suggests that DON contamination in the Chinese market is serious, and the contamination risk deserves attention. Essential preventive measures should be implemented to ensure food safety and human health.


Sign in / Sign up

Export Citation Format

Share Document