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In this study, we developed a monoclonal antibody (mAb)-based colloidal gold immunochromatography assay (CG-ICA) strip for the rapid and sensitive detection of flubendiamide (FBD) in food samples. Our anti-FBD mAb 2B1 was highly specific and had a half-maximal inhibitory concentration (IC50) of 1.55 ng/mL under optimal conditions. It belongs to the IgG2a isotype and has a Kaff value of 1.52 × 109 mol/L. The strip provided a visual detection limit of 50 ng/g for both grapes and tomatoes, with a cut-off value of 1,000 ng/g and these qualitative results were observed within 15 min. For quantitative analysis, the calculated detection limits were 6 ng/g and 5 ng/g in grapes and tomatoes, respectively. The average recoveries of FBD ranged from 88.8% to 111.8% in grapes and 94.5% to 110.6% in tomatoes. The proposed strip assay is highly practical for screening FDB in food samples. [ABSTRACT FROM AUTHOR]

A monoclonal antibody against triamcinolone acetonide (TCA) and budesonide (BUD) was prepared using a hapten that was generated by introducing a carboxyl group into the structure of TCA. Based on the prepared monoclonal antibody, a gold nanoparticle-based lateral-flow immunoassay (GLFA) was developed with the ability to screen TCA and BUD in milk. The visible limits of detection of the GLFA for the analysis of TCA and BUD were 0.1 and 0.5 ng/mL with a cutoff value of 5 and 10 ng/mL, respectively, in milk. Average recoveries of TCA and BUD in milk were 92.0–102.2% and 96.0–98.8% with a good correlation between the results from the GLFA and LC-MS/MS analysis. These results demonstrated that the GLFA method for the rapid detection of TCA and BUD in milk samples is reliable and sensitive. [ABSTRACT FROM AUTHOR]

Butralin is a widely used dinitroaniline herbicide. Butralin residues in vegetables or fruits represent a threat to human health. In this study, we developed a rapid and sensitive gold-based lateral flow immunoassay (LFIA) for butralin detection in tomato and green pepper samples based on a screened monoclonal antibody (mAb) against butralin. The mAb possessed a half-maximal inhibitory concentration (IC50) of 12.7 ng/mL, with no cross-reactivity toward other dinitroaniline herbicides. The established LFIA strip had a visible limit of detection (LOD) of 50 ng/g and a cut-off value of 2000 ng/g in tomato and green pepper samples. According to the calibration curves for quantitative analysis, the calculated LODs of the LFIA strip were 4.7 ng/g and 4.3 ng/g in tomato and green pepper, respectively. The results were obtained within 10 min. The average recoveries ranged between 95.4% and 109.6% with a coefficient of variation (CV) of 4.3% to 7.1% in tomato samples and between 94.8% and 109.1% with a CV of 3.9% to 6.1% in green pepper samples. These data suggested that our proposed LFIA is a sensitive, specific, and reliable method for the rapid detection of butralin in real samples. [ABSTRACT FROM AUTHOR]

In this study, a monoclonal antibody (mAb) 1G5 against novobiocin with high sensitivity and specificity was prepared from a newly-designed hapten. According to the results of an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA), the 50%-inhibitory concentration of the anti-novobiocin mAb was 6.9 ng/mL and the cross-reactivity was less than 0.1% to its analogues. Furthermore, a rapid colloidal gold immunochromatographic assay (ICA) was successfully developed for the determination of novobiocin in spiked samples. Two calibration curves were established respectively, for beef and chicken samples. The ICA results showed a visual colorimetric value of 50 ng/mL and a cut-off value of 300 ng/mL in beef samples. The ICA results of chicken samples were almost the same as that of beef. When quantitative detection was performed using a strip reader, the detection ranges for quantitative analysis in beef and chicken were 23.7–287.5 and 19.7–263.8 µg/kg respectively. Recoveries were between 82.7 and 95.3% for beef samples with the coefficient of variation (CV) ranging from 2.5 to 5.1%. Recoveries were in the range of 89.6–105.5% with the CV ranging from 2.9% to 6.3% for chicken samples. Importantly, these results from the ICA were highly consistent with the results obtained by LC-MS/MS. Therefore, this ICA could be used as an alternative means for the rapid determination of NOV in a large number of beef and chicken samples. [ABSTRACT FROM AUTHOR]

We have developed a sensitive and rapid gold nanoparticle-based immunochromatographic strip (GNP-ICS) for the detection of bifenthrin (BF) using an anti-BF monoclonal antibody (mAb). When used in indirect competitive enzyme-linked immunosorbent assay (icELISA), the specific anti-BF mAb (3D1) had a half-maximal inhibitory concentration (IC50) and limit of detection (LOD) of 59 and 15 ng mL−1 respectively. Additionally, its cross-reactivity (CR) with other pyrethroids was negative. The developed GNP-ICS assay based on the GNP-labelled mAb was specific and sensitive for determining BF, with a cut-off value of 1,000 ng mL−1, and a visual LOD (vLOD) value of 50 ng mL−1. Furthermore, the developed icELISA and GNP-ICS were applied with a simple pre-treatment to determine BF-spiked vegetable samples, and the recoveries were validated using gas chromatography-mass spectrometry (GC-MS). The results revealed that the developed GNP-ICS was reliable for the detection of BF in practical samples. [ABSTRACT FROM AUTHOR]

Three supramolecular gelators (2a, 3a, 3b) of a benzene 1,3,5-tricarboxamide (BTA) motif were synthesized and studied for their gelation behavior. 3a and 3b were designed and synthesized for the first time. 3a showed excellent gelation behavior in a variety of aromatic solvents with minimum gel concentration in the range of 0.7% (w/v)–2.1% (w/v). The morphology of the stable gels indicated the formation of a highly entangled fiber network in mesitylene and xylene. FT-IR studies revealed an evident role of intermolecular hydrogen bonding in the self-assembly process. UV studies showed that π–π interaction is the driving force for the gelator to form a gel. The experiment results of the aromatic solvents recovery showed that the BTA-based gelator with naphthyl group exhibits excellent phase selectivity on gel mesitylene and xylene from a mixture of aromatic solvent and water when applied in the powder form at 3.2% (w/v) in mesitylene and 4.2% (w/v) in xylene. π-π stacking between phenyl groups and naphthyl groups of gelator might provide an additional driving force for the formation of a dense three-dimensional network capable of phase-selective gelation of aromatic solvents from a mixture of aromatic solvent and water. The experiment results of the dye removal indicated that the entangled fibrous network and the rheological property enable the BTA-based phase-selective gelator to be used as recyclable materials for removing toxic dyes from a mixed solution of water and organics with efficiency as high as 99.5%. And 3a can gel crude oil from a mixture of water and oil by using crude oil as carrier solvents. Thus, these smart systems possess the potential to be used effectively in water purification and oil spills remediation. [ABSTRACT FROM AUTHOR]

The purposes of this study were to provide palynological information about apricots and to reveal the relationships among six ecological groups of apricots by describing the morphological characteristics of their pollen. The pollen grains of 175 accessions belonging to three species (Prunus armeniaca L., Prunus sibirica L., and Prunus mume Sieb. et Zucc.) of Prunus were examined using light microscopy and scanning electron microscopy. The pollen grains were isopolar monads, radially symmetric, medium to large in size, prolate or subprolate, and 3-colporate. Most pollen grains exhibited striate exine ornamentation, and a few exhibited striato-reticulate or cerebroid exine ornamentation. Cluster analysis divided the six ecological groups into two groups: one including the Central Asian, North China, and Dzhungar-Ili ecological group accessions and another including the Northeast Asian, European, and East China ecological group accessions. Principal component analysis revealed that equatorial diameter, colpus length, colpus width, and ridge width were the most important metrical pollen traits, and can be used as powerful diagnostic characters in apricot identification. We speculated that the cultivated apricots in Xinjiang were domesticated from wild apricots from the Ili Valley. This study describes the morphological characteristics of apricot pollen grains and provides some morphological information for future studies on the phylogenetic relationships of apricots. [ABSTRACT FROM AUTHOR]

In this study, a high sensitivity and specificity monoclonal antibody (mAb) was developed based on the hydroxy and carboxy-termini of ochratoxin A (OTA). A fluorescent microsphere immunochromatographic test strip (FM-ICTS) was assembled for the rapid detection the OTA in rice flour. Some relevant parameters were optimized including the best concentration of coating antigen and optimal diluent buffer composition. Under optimal conditions, the strip assay had a visual limit of detection (LOD) of 2 ng/mL and a cut-off value of 16 ng/mL for OTA in rice flour samples. By means of a strip scan reader, we obtained a quantitative measurement for OTA with an LOD of 1.27 ng/mL. No significant difference in the strip test results was seen when compared to an ic-ELISA assay or LC–MS/MS. This also shows, therefore, that the FM-ICTS has potential application for rapid and accurate quantitative detection in the market place. [ABSTRACT FROM AUTHOR]

In this study, a monoclonal antibody with selectivity for clopidol was produced based on a new hapten. The 50% inhibition concentration (IC50) for the developed ic-ELISA was 0.275 ng/mL. Cross-reactivity tests showed that the monoclonal antibody had high specificity for clopidol. Using this antibody, a lateral-flow colloidal gold immunoassay (LCGA) was created for the rapid screening of clopidol in raw chicken samples. With the naked eye, the cut-off value of the strip assay was 5 μg/kg for clopidol in chicken samples. Therefore, this LCGA provides a sensitive and rapid method for on-site detection of clopidol in chicken samples. [ABSTRACT FROM AUTHOR]

In developing countries, pesticides such as triazophos (TZP) are widely used in agriculture. However, the misuse TZP poses a threat to human health and the environment due to its high chemical and photochemical stability. In this study, we developed a lateral flow assay to determine TZP in cucumber. We produced anti-TZP monoclonal antibody with half inhibitory concentration of 2.013 ng/mL according to ELISA. Under optimum conditions, the lateral flow assay had TZP cut-off values of 100 ng/mL in 0.01 M PBS and 250 ng/mL in cucumber, and the results could be visualised with the naked eye in 5 min. our findings revealed that lateral flow assay is a rapid and sensitive method for detect TZP in cucumber. [ABSTRACT FROM AUTHOR]

Citreoviridin (CTV) is a toxic secondary metabolite that can be found in mouldy cereals. In this study, a sensitive and ethanol-tolerant anti-CTV monoclonal antibody (6B2) was produced with a 50% inhibition concentration of 4.1 ng/mL and then labelled using gold nanoparticle (GNP). Based on competitive inhibition of the binding of CTV-COOH-BSA conjugate sprayed onto a membrane to limited GNP-labelled antibody by free CTV in the samples, an easy-to-operate immunochromatographic strip (ICS) was developed for the fast screening of CTV in rice. The results are seen as a colour change within 5-10 min. We used relatively safe ethanol instead of highly toxic methanol or chloroform as the extraction solution and found a visible detection limit of 100 μg/kg and cut-off value of 1000 μg/kg. The developed ICS assay worked well and represented a reliable, safe, fast and a highthroughput method for the detection of CTV residues in rice samples. [ABSTRACT FROM AUTHOR]

In this study, an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) and a gold immunochromatographic assay were developed to detect the furaltadone metabolite, 3-amino-5-morpholinomethyl-2-oxazolidinone (AMOZ). The detection of AMOZ was based on the AMOZ derivative 3-([2-nitrophenyl] methyleneamino)-5-morpholinomethyl-2-oxazolidinone (2-NPAMOZ). The monoclonal anti-2-NPAMOZ antibody 4G11, was prepared and exhibited a 50%-inhibitory concentration (IC50) of 0.049 ng/mL. Its cross-reactivity with structurally related analogues was less than 3%. This immunochromatographic assay was assembled for the rapid screening of AMOZ in catfish samples. The strip assay had a cut-off value of 0.1 μg/kg and a limit of detection (LOD) of 0.009 μg/kg. Analysis of AMOZ in catfish indicated that the results from the strip assay were highly comparable to results obtained using ic-ELISA and LC-MS/MS. Therefore, the colloidal gold (CG) immunoassay is a sensitive screening method for the detection of AMOZ residues in catfish samples. [ABSTRACT FROM AUTHOR]

In this study, we developed a monoclonal antibody against picoxystrobin (PIC). After cell fusion, four cell lines (3C2, 4D1, 4G4 and 5D4) capable of producing monoclonal antibodies against oxystrobin were obtained. The monoclonal antibody produced by the cell line 3C2 was the most sensitive to PIC, and its IC50 value was 0.1 ng/ml. The monoclonal antibody was then used to prepare immunochromatographic strips, and its cut-off values in both phosphate-buffered saline solution and cucumber samples were 50 and 100 ng/ml, respectively. It was concluded that the ICS can sensitively and rapidly detect PIC in cucumber samples. [ABSTRACT FROM AUTHOR]

In this study we developed a rapid and simple assay to detect RFP in fish using an immunochromatographic assay. We produced a sensitive and selective monoclonal antibody against RFP with a half-maximal inhibitory concentration (IC50) of 10.7 ng/mL. Fish samples were extracted with ethyl acetate, then centrifuged at 8000 rpm for 10 min, and concentrated by drying over nitrogen. We found under optimal conditions, that the RFP cut-off limits for the test strip was 10 µg/mL in both 0.01 M phosphate buffered saline and fish samples, and each test could be completed within 5 min. Therefore, immunochromatographic test can be used as a reliable, rapid, and sensitive method for the detection of RFP in fish. [ABSTRACT FROM AUTHOR]

Tricaine (TMS) is usually used as an anesthetic in the transportation of aquatic animals. However, when consumed, the numerous residual drug residues found in fish can cause a high risk to human health. Therefore, it is important to develop a rapid and sensitive method for the detection of this drug in food. Here we have developed a novel lateral-flow immunochromatographic strip (LF-ICS) method for the detection of TMS in fish samples, using a very effective anti-TMS monoclonal antibody with a half-maximal inhibitory concentration value of 31.79 ng/mL. After the K2CO3 and coating antigen concentrations were optimized in phosphate buffered saline (pH 7.4), the LF-ICS was used to determine TMS levels in fish samples spiked with varying concentrations of the drug. Following this, the values for the visual limit of detection and the cut-off for TMS were found to be less than 0.1 and 1 μg/mL, respectively. These results indicated that our developed LF-ICS is applicable for on-site screening of TMS in fish samples. [ABSTRACT FROM AUTHOR]

In this study, we produced a monoclonal antibody (mAb) 2F7 against cadmium (Cd) with IC50 of 0.20 ng/mL. The cross-reactivity of mAb 2F7 with other eight metals was < 1%. A fluorescent immunoassay strip was developed for the determination of Cd in rice. The cut-off value by visual inspection of the test strip was 50 μg/kg, and the quantitative detection range determined by the strip reader was 3.86–48.92 μg/kg. Both ic-ELISA and the fluorescent immunoassay strip can be used to detect Cd rice. Therefore, our developed fluorescent immunoassay strip may be an effective tool for detecting Cd in rice. [ABSTRACT FROM AUTHOR]

Lead (Pb) is a toxic metal that can accumulate in the body and negatively impact human health. In this study, we prepared a highly sensitive and specific monoclonal antibody, 2C3, that can recognize Pb(II) with an IC50 and linear range of 0.5 ng/mL and 0.08–1.86 ng/mL, respectively. Additionally, based on this antibody we developed a fluorescent test strip, which can be used for both qualitative and quantitative detection of Pb(II) in brown rice with a detection range of 4.67–47.8 ng/mL. Therefore, the method we developed has high sensitivity suitable for the detection of Pb(II) in brown rice. [ABSTRACT FROM AUTHOR]

In this study, we produced a specific monoclonal antibody (mAb) against triadimefon (TDF) and triadimenol (TDN). The half-maximal inhibitory concentration for TDF and TDN was 5.25 and 9.98 ng/mL, respectively, with a linear detection range (IC20–IC80) of 1.09–25.35 and 2.29–43.61 ng/mL, respectively. Subsequently, we developed a colloidal gold immunochromatography test strip for the analysis of TDF and TDN in tomato. The results obtained from the colloidal gold immunochromatography test strip were in accordance with those obtained from the indirect competitive enzyme-linked immunosorbent assay. The colloidal gold immunochromatography test strip is efficient and suitable for on-site detection of TDF and TDN. [ABSTRACT FROM AUTHOR]

The medicinal properties and toxicity of aconitine in traditional Chinese medicine have caused widespread concern. In this study, we screened a highly specific and sensitive monoclonal antibody with an IC50 of 3.65 ng/mL generated by immunizing mice and cell fusion, and the limits of detection of the ic-ELISA were 1.13 and 11.76 ng/mL. We then developed a colloidal gold test strip based on the antibody. For rapid detection of aconitine in herbs, the visual limit and detection limit of the test strip are 10 and 25 ng/mL, respectively; the results are obtained within 5 min and are visible to the naked eye. Therefore, the colloidal gold test strip is very suitable for on-site detection and quality screening of aconitine in Chinese herbal medicine. [ABSTRACT FROM AUTHOR]

A monoclonal antibody against carazolol (CRZ), 2F5, was generated for the construction of an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) and an immunochromatographic strip for detection of CRZ in milk and pig kidney samples. The antibody had a half-maximal inhibitory concentration of 0.29 ng/mL; its limit of detection was 0.068 ng/mL, and its linear range of detection was 0.137–0.638 ng/mL. For CRZ in milk samples and porcine kidney samples, the detection limits for this strip were 0.25 and 2.5 ng/mL, respectively. Analysis of CRZ in milk samples showed that the results obtained by immunochromatographic strip were consistent with those obtained by ic-ELISA. Therefore, the CG immunoassay is a sensitive screening method for semi-quantitative and qualitative detection of residual CRZ in milk and porcine kidney samples. [ABSTRACT FROM AUTHOR]

Aminophylline (AMP), a bronchodilator drug, is a modified form of theophylline (the pharmacological active ingredient). AMP is often given to treat respiratory diseases, including bronchial asthma, blocked emphysema, panting bronchitis, and cardiogenic asthma. In this study, we developed a rapid and sensitive method to determine AMP concentration in mouse serum. A sensitive monoclonal antibody against AMP was produced by immunizing BALB/c mice with a well-characterized AMP2-keyhole limpet hemocyanin and coating antigen (hapten-AMP1-OVA). The coating antigen and goat anti-mouse IgG antibody were sprayed onto a nitrocellulose membrane representing the test and control lines, respectively. Under optimized conditions, the cut-off limits of the test strip were 50 ng/mL in 0.01 M phosphate buffered saline (pH 7.4) and 250 ng/mL in serum. The results were obtained within 10 min and revealed that this immunochromatographic strip test is a sensitive, rapid, and simple tool for the detection of AMP in serum. [ABSTRACT FROM AUTHOR]

In this study, a kitasamycin (KIT) hapten was prepared through the o-carboxymethoxylamine method and used to produce a monoclonal antibody against KIT and josamycin (JOS). The half inhibition concentration for an indirect competitive enzyme-linked immunosorbent assay was 1.49 and 2.67 ng/mL, respectively. Based on this antibody, a gold immunochromatographic assay (GICA) was developed for the detection of KIT and JOS residues in milk and egg samples. A hand-held strip scanner was used for quantitative analysis, with limits of detection for KIT and JOS of 1.51 and 1.91 μg/L in milk, and 3.0 and 2.72 μg/kg in eggs. The proposed GICA was validated by LC–MS/MS, which indicated that the GICA method would be a useful tool for the on-site detection of KIT and JOS residues in milk and egg samples. [ABSTRACT FROM AUTHOR]

An anti-cimaterol (cima) monoclonal antibody, 2H8, was prepared and used to develop an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) and an immunochromatographic test strip assay for the detection of cima, a newly described β-agonist. The half-maximal inhibitory concentration of the antibody was 1.56 ng/mL, and no cross-reactivity with other β-adrenergic agonists was observed. The antibody's limit of detection was 0.416 ng/mL, and its linear range of detection was 0.416–5.868 ng/mL. The recovery rates of cima in swine urine ranged from 86% to 92.5%, and the test strip had a cut-off value of 10 ng/mL. Both ic-ELISA and the developed strip assay are effective when detecting cima in swine urine. [ABSTRACT FROM AUTHOR]

Praziquantel (PZQ) is a broad-spectrum antiparasitic drug used in mammals and fish. In this study, we developed an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) for the detection of PZQ residues. The hapten PZQ-HS produced by introducing an amino group at a benzene ring synthesized the immunogen and the coating antigen with carrier proteins. Highly sensitive monoclonal antibodies (mAbs) were prepared following mouse immunization and cell fusion. Under optimum conditions, the half maximal inhibitory concentration of the cell line 4E9 was 7.4 ng/mL, and the working range was 2.4–22.8 ng/mL. Immunochromatographic strips (ICS) were developed for the rapid detection of PZQ residues in mackerel. The reliability of the ICS assay was verified with PZQ-negative mackerel and confirmed by HPLC/MS. The cutoff value for ICS was 50 ng/mL PZQ. Our findings revealed that ic-ELISA and ICS can be used for the rapid detection of PZQ in mackerel. [ABSTRACT FROM AUTHOR]

This study developed a sensitive monoclonal antibody, 3A3, to salinomycin (SLM) and methyl salinomycin (MLN). The monoclonal antibody 3A3 is highly specific for SLM with an antibody halfinhibitory concentration (IC 50) of 0.86 ng/mL, a detection limit of 0.28 ng/mL, and a linear detection range of 0.28–2.26 ng/mL. The cross-reaction values of SLM and MLN were 100% and 74.48%, respectively. The recovery of honey samples ranged from 94.6% to 100.4%, thus indicating that this analytical method can be used for the analysis of real honey samples. In addition, immunochromatographic bands were developed for qualitative, semi-quantitative and speckle detection analysis. The critical values of SLM and MLN in honey were 40 and 40 ng/mL, respectively. The results showed that these analyses can be used for real samples, with the most stringent MRL of 40 ng/mL, for SLM and MLN. [ABSTRACT FROM AUTHOR]

A monoclonal antibody (mAb), 2C9, selective for four eugenol compounds, was developed based on the eugenol derivatives (Eug-1). The semi-inhibitory concentrations (IC50) of this antibody against eugenol, isoeugenol, methyl eugenol, and methyl isoeugenol were 0.043, 0.302, 0.016, and 0.082 μg/mL, respectively, and the detection limits (LOD) were 0.012, 0.070, 0.004 and 0.024 μg/mL. With the exception of isoeugenol, which had cross-reactivity of less than 15%, the cross-reactivity of the other compounds was good, ranging from 52.4% to 269%. In the ic-ELISA recovery test, recovery was between 80% and 94%, indicating that the method was suitable for analysis of eugenol compounds in water. The cut-off values of the immunochromatographic strips for the four compounds in water were 5, 100, 100, and 100 μg/mL, respectively, indicating that the ic-ELISA and immunochromatographic strips we developed can be used to rapidly detect eugenol compounds in water. [ABSTRACT FROM AUTHOR]

In this study, we prepared a monoclonal antibody against pyrimethanil, for which we first derived its hapten according to the structural formula of pyrimethanil; we used indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) to screen positive mice for cell fusion; finally, we developed five cell lines (1A5, 1E7, 3A6, 3H12 and 5D4) that produced monoclonal antibodies to pyrimethanil. The monoclonal antibody produced by each cell was detected by ic-ELISA, and the monoclonal antibody produced by the 1E7 cell strain was found to be the most sensitive to pyrimethanil. The IC50 value of this antibody was 4 ng/ml. After using this monoclonal antibody, i.e. 1E7, to perform immunocolloidal gold strip treatment on cucumber samples, the PBS and the cucumber samples cutoff value of Immunochromatographic strips (ICS) was found to be 50 ng/ml; We conclude that ICS can rapidly detect pyrimethanil in cucumber samples. [ABSTRACT FROM AUTHOR]

A rapid, specific and sensitive method based an immunochromatographic strip test has been developed for the determination of sodium nifurstyrenate (NFS) residues in fish. Sample preparation procedure includes ultrasonic bath extraction with acetonitrile, sample centrifugation at 8000 rpm for 10 min, filtration through the 0.22 µm membrane filter, and drying over nitrogen (60°C) and res-suspension. The antigen (NFS-ovalbumin) and a goat anti-mouse IgG antibody were drawn onto a nitrocellulose membrane as the test line and control line, respectively. Under optimized conditions, the NFS cut-off limits for test strips was determined as 5 ng/mL in 0.01 M phosphate buffered saline and 10 ng/mL in fish. Results were obtained within 5 min. Our data suggests this immunochromatographic assay can be used for the sensitive, rapid, and specific on-site screening for NFS in fish. [ABSTRACT FROM AUTHOR]

A highly sensitive, specific, and rapid immunochromatographic assay for halofuginone (HFG) has been developed. A well-characterized immunogenic conjugate of HFG with bovine serum albumin was produced using the N,N″-Carbonyldiimidazole method. A sensitive monoclonal antibody specific for HFG was then generated by immunizing BALB/c mic with the HFG conjugate. The antigen, HFG-CDI-ovalbumin and goat anti-mouse IgG were attached to a nitrocellulose membrane as the test line and the control line, respectively to produce an immunochromatographic test strip for the rapid detection of HFG in milk. Under optimized conditions, the detection limits of the semi-quantitative test strip for HFG were as low as 50 ng/mL in 0.01 M PBS (pH 7.4) and 100 ng/mL in milk. All the results were obtained within 5 min. The newly developed immunochromatographic assay provides a sensitive, rapid, and specific procedure for on-site screening for HFG. [ABSTRACT FROM AUTHOR]

The problem of waste oil is a food safety issue that requires urgent resolution. In this study, a novel hapten was designed for the rapid detection of capsaicinoids, a marker of waste oil, and a monoclonal antibody (MAb) 5D7 was generated that is specific for three major capsaicinoids: capsaicin (CPC), dihydrocapsaicin (DCPC), and N-vanillylnonanamide (N-V). The half maximal inhibitory concentrations of MAb 5D7 for CPC, DCPC, and N-V were 1.12, 0.8, and 0.87 ng/mL, respectively. An immunochromatographic strip test based on MAb 5D7 was established for these three capsaicinoids, with visual inspection limits of <1.0 ng/mL, which satisfies the requirement for the rapid on-site inspection of waste oil. [ABSTRACT FROM AUTHOR]

Humans and animals are exposed to mycotoxins naturally present in foods. Ochratoxin A (OTA), one of the most abundant and toxic mycotoxins, is ubiquitous in nature and harmful to humans and animals. In this study, we developed a rapid, simple, specific, and sensitive lateral-flow immunochromatographic assay for detection of OTA in 0.01 M phosphate-buffered saline solution (PBS) (pH 7.4) and in red wine. We produced sensitive and selective monoclonal antibody against OTA. Under optimized conditions, the cut-off limit of the test strip was 10 ng/mL OTA in 0.01 M PBS (pH 7.4) and in red wine. The results were obtained within 10 min. Therefore, our developed method is useful for the detection of OTA in red wine. [ABSTRACT FROM AUTHOR]

In this paper, we describe the development of a rapid, simple, specific, and sensitive immunochromatographic strip test based on an antibody-antigen reaction for detection of tulathromycin (TULA) in samples of 0.01 M PBS pH 7.4, pure milk and honey. The monoclonal antibodies specifically recognized the corresponding antigens produced in our laboratory. Under optimized conditions, the cut-off limits of the test strips for TULA in 0.01 M PBS pH 7.4 was found to be 2.5 ng/mL. Meanwhile, with simple preparation for detection in pure milk and honey samples, the cut-off limits for TULA were found to be 5 and 10 ng/mL, respectively. Each test can be evaluated in 5 min. In summary, this lateral-flow device provides a sensitive, effective, specific, and rapid method for detection of TULA residues in food matrix. [ABSTRACT FROM AUTHOR]

The presence of pesticide residues in crops is a significant public concern. Due to the large number of samples and pesticides, a reliable, simple, cost-effective, and high-throughput analytic method is required. In this study, we developed a gold nanoparticle (GNP) immunochromatographic assay (ICA) for the rapid detection of 6-benzylaminopurine (6-BA) residues in bean sprouts. A monoclonal antibody against 6-BA, having a half-maximum inhibition concentration of 2.25 ng/mL, was labeled with GNPs and fixed onto a glass fiber membrane to create a conjugate pad. Coating antigen and goat anti-mouse antibody were sprayed onto a nitrocellulose membrane to form the test line and control line, respectively. The visual limit of detection and cutoff limit of ICA were 10 and 80 ng/g in bean sprouts, respectively. The results of ICA were obtained within 10 min with the naked eye. Therefore, ICA is a rapid tool for the on-site screening and detection of 6-BA in bean sprouts. [ABSTRACT FROM AUTHOR]

Procaine (PRC) is a local anaesthetic used in the treatment of several disease related to ageing, asthma, and arthritis. In this study, we describe a rapid, sensitive, simple, and accurate method for the determination of PRC in milk, using an immunochromatographic test strip. For the immunochromatographic test, antigen (PRC-bovine serum albumin) and goat anti-mouse IgG were drawn onto a nitrocellulose membrane representing the control line and test line. The test was developed with a sensitive monoclonal antibody specific for PRC, generated by immunizing BALB/c mice with a well-characterized PRC- Keyhole limpet hemocyanin conjugate, produced in our laboratory. Under optimized conditions, the semi-quantitative test strip was able to detect PRC at concentrations down to 1 ng/mL in both 0.01 M phosphate buffer saline (pH 7.4) and milk samples. All results were obtained within 5 min. Our data indicate that the immunochromatographic assay is capable of sensitive, rapid, and specific on-site screening of PRC. [ABSTRACT FROM AUTHOR]

Using immunological and cell fusion technology, group-specific monoclonal antibodies were produced against cyproheptadine. The 50% inhibitory concentration of the antibody for cyproheptadine was 0.37 ng/mL, the linear range was 0.16-0.85 ng/mL, and recoveries of antibody in spiked negative pig urine were 80-120%. An ultrasensitive immunochromatographic strip, based on the antibody, was developed for the rapid detection of cyproheptadine in pig urine. The test strip had a cut-off value of 5 ng/mL. [ABSTRACT FROM AUTHOR]

Clonidine (CLO) preferentially stimulates central α-2-adrenoceptors and causes both desirable and undesirable effects. Undesirable effects include sedation and withdrawal reactions, which occur as a sudden rise in arterial pressure, nervousness, agitation, and increased heart rate. An immunochromatographic test strip was developed for the rapid simultaneous detection of CLO and its cross-reactivity with apraclonidine (ACLO) in pig urine. The antigen CLO-OVA and goat anti-mouse IgG were attached to a nitrocellulose membrane as control line and test line. The cut-off limits of the test strips for CLO and ACLO were found to be 2.5 ng/mL in both 0.01 M PBS (pH 7.4) and pig urine. All the results were obtained within 5 min. The results revealed that the developed method is a sensitive, rapid, and simple tool for the detection of CLO and ACLO. [ABSTRACT FROM AUTHOR]

A sensitive monoclonal antibody (mAb) (1H1) against fumonisin B1 (FB1) was produced in our laboratory. A rapid, simple, and an immunochromatographic strip has been developed for the ultrasensitive detection of FB1 in corn samples. Under the optimized condition, the cut-off limits of test strips for FB1 were found to be 50 ng/mL in 0.01 M PBS and 25 ng/mL in corn samples. Results could be obtained within 5 min. The results revealed that the developed method is a rapid, sensitive, and simple tool for the detection of FB1. [ABSTRACT FROM AUTHOR]

A clorprenaline (CLP) monoclonal antibody, 4G1, raised against the CLP-hapten was successfully prepared for the development of indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) and immunochromatographic assays for the detection of CLP in pig urine samples. The half maximal inhibitory concentration of the antibody was 0.435 ng/mL, and the limit of detection was 0.104 ng/mL. The linear range was 0.104-1.818 ng/mL, and cross-reactivity with the CLP analogue was <5%. In the spiked sample and recovery test, the recovery ranged from 81.8% to 100.5%, indicating that the ic-ELISA was suitable for CLP analysis in pig urine. The critical value of the immunochromatographic strip in pig urine was 10 ng/mL and could be used for semi-quantitative analysis of CLP. Thus, this immunochromatographic strip was suitable for quickly and sensitively detecting CLP residues in pig urine samples. [ABSTRACT FROM AUTHOR]

An anti-pefloxacin (PEF) monoclonal antibody (mAb), an indirect competitive enzyme-linked immunosorbent assay and lateral-flow test strip methods were developed to detect fluoroquinolone (FQ) residues in chicken muscle samples. Under optimised conditions, the anti-PEF mAb showed reasonable cross-reactivity with nine FQs with a limit of detection of 0.082 ng/mL assayed in 0.01 M phosphate buffered saline (PBS) solution. The intra- and inter-assay recoveries from spiked samples were within the range of 62.42-111.47% and 63.5-113.79%, respectively. The visual cut-off values of the lateral flow test strip in 0.01 M PBS and in food matrices were within the range of 2.5-50 ng/mL and 5-100 µg/kg, respectively. These results show that the anti-PEF mAb immunoassay and lateral flow test strip methods are suitable for simultaneous detection and routine monitoring of FQ residues in food. [ABSTRACT FROM AUTHOR]

Zearalenone (ZEN) is a mycotoxin produced by fungal species which are widespread in nature and commonly contaminate many cereal grains, such as wheat, maize, corn, barley, and other cereal grains. An immunochromatographic (ICA) test strip was developed for the rapid simultaneous detection of ZEN and its metabolite in corn flour samples. For the ICA test, antigen (ZEN-BSA) and goat anti-mouse IgG were, respectively, drawn on nitrocellulose membrane as control line and test line. Under the optimized condition, the cut-off limits of test strips for ZEN, α-ZAL, and β-ZAL were found to be 0.5 ng/mL in 0.01 M PBS and 50 ng/mL in corn flour samples, meanwhile α-ZOL, β-ZOL, and ZEA were found to be 1 ng/mL in 0.01 M PBS and 75 ng/mL in corn flour samples. Our data indicate that the ICA is sensitive, rapid, cost-effective, and specific on-site screening for ZEN and its metabolite. [ABSTRACT FROM AUTHOR]

Following the steps of antigen synthesis, immunization, cell fusion, ascites preparation and purification, a maduramicin (MD) monoclonal antibody (mAb) was produced. This MD-mAb demonstrated a 50% inhibition concentration value of 3.75 ng/ml, an affinity constant of 3.70  × 1010 l/mol, and the isotype was IgG3. The MD-mAb has no cross-reactivity with other polyether antibiotics. Using this MD-mAb, a gold immunochromatographic assay was developed to detect MD residues in chicken breast and egg samples. For semi-quantitative detection by the naked eye, the visual limit of detection was 5 ng/g in chicken breast, 10 ng/g in egg. Quantitative results can be obtained by a hand-held strip scan reader, with the detection range of 5.11-19.34 ng/g in chicken breast and 6.46-27.87 ng/g in egg. The strip test took 10 min to run in total. This strip assay is suitable for on-site detection of MD residues in chicken breast and egg samples. [ABSTRACT FROM AUTHOR]

An ultrasensitive monoclonal antibody-based gold nanoparticle immunochromatographic strip assay and indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) were developed to detect florfenicol (FF) and thiamphenicol (TAP) in egg samples. The ic-ELISA, with optimized pH, methanol content and sodium chloride content, exhibited an IC50 value of 0.2 ng/mL for FF and 0.27 ng/mL for TAP, with the working range of 0.05-0.77 and 0.05-1.42 ng/mL, respectively. The optimized ic-ELISA showed negligible cross-reactivity with other phenols and broad-spectrum antibiotics. The recoveries in egg samples using the ic-ELISA ranged from 84% to 115% with a coefficient of variation of less than 5%. Based on this monoclonal antibody, a rapid and ultrasensitive immunochromatographic strip assay was developed with a cutoff value of 1 ng/mL for FF and TAP. Our results indicated that both developed methods were highly useful for screening FF and TAP in eggs. [ABSTRACT FROM AUTHOR]

Flunixin meglumine (FM) is a novel nonsteroidal anti-inflammatory drug for animals, which has antipyretic, analgesic, and anti-inflammatory effects. The drug, which was originally used to relieve inflammation in horses, musculoskeletal disorders, and pain, has been approved for use in endotoxemia, infectious diseases in swine, etc. A sensitive anti-FM monoclonal antibody 2H4 was prepared and used to develop an indirect competitive enzyme-linked immunosorbent assay and immunochromatographic strip assay for the detection of FM in milk. The complete antigen and coating antigen were conjugated with bovine serum albumin and ovalbumin, respectively. The monoclonal antibody 2H4, with a half inhibition concentration of 0.29 ng/mL, had a limit of detection of 0.432 ng/mL and a linear range of detection of 0.08664-0.97226 ng/mL. A sensitive and convenient immunochromatographic strip assay was developed with an FM cutoff value of 0.29 ng/mL. The developed methods were suitable for the detection of FM in milk. [ABSTRACT FROM AUTHOR]

A monoclonal antibody (mAb) directed against phenylethanolamine A (PEA) was successfully prepared with the immunization of mice and cell fusion, and used to develop a detection method for a colloidal gold immunoassay. The 50% inhibitory concentration of mAb PEA-2G10 was 0.213 ng/mL, the limit of detection was 0.033 ng/mL, and its detection range 0.033-0.679 ng/mL. The recovery rate for PEA in swine urine was 84.5-90.8%, with good stability and accuracy. “Dry” immunoassay test strips were successfully prepared based on antibody 2G10. When the strip was tested in swine urine, the cutoff value for PEA was 5 ng/mL, with highly sensitivity. The method developed here can be used to test swine urine on-site for the rapid detection of PEA. [ABSTRACT FROM AUTHOR]

Vitamin B2 (riboflavin) is a water-soluble vitamin that has important roles in human health. In this study, we developed a sensitive and specific monoclonal antibody-based indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) and lateral-flow immunochromatographic assay (ICA) strip for the rapid detection of vitamin B2. Following routine fusion and selection, the optimum monoclonal antibody against vitamin B2 was obtained. The 50% inhibitory concentration and limit of detection of ic-ELISA were 8.18 and 1.80 ng/mL, respectively. The cut-off value of the lateral-flow ICA strip was 50 ng/mL. The results revealed that our developed methods are suitable for the on-site detection and mass screening of vitamin B2 in food and pharmaceutical products. [ABSTRACT FROM AUTHOR]

A novel and highly sensitive immunochromatographic strip based on a monoclonal antibody (3A9) was developed for the detection of cadmium in tap water. The 50% inhibition concentration of the antibody, which showed no cross-reactivity with other heavy metal ions, was 0.45 ng/mL and it recognized Cd(II)-1-(4-isothiocyanobenzyl) ethylenediamine-N,N,N′,N′-tetraacetic acid (EDTA) (Cd(II)-ITCBE) and not metal-free ITCBE and EDTA. The cutoff value for semi-quantitative detection of the strip was 5 ng/mL and the lower limit of detection for quantitative detection was 0.2 ng/mL using a scanning reader. The percent recovery ranged from 107.6% to 132% in tap water samples. [ABSTRACT FROM AUTHOR]

Objectives The protective effects of hypothermia on acute stroke have been demonstrated in many studies. However, its underlying mechanisms have not been thoroughly elucidated. Following an ischemic stroke event, microglia undertakes an early ‘healthy’ M2 phenotype and gradually transform into a ‘sick’ M1 phenotype over time. This transformation of polarity of microglia has influence on the degree of damage following a stroke. This study investigated the effects of mild focal hypothermia on microglia polarization following ischemic stroke. Methods Transient cerebral ischemic models were created by intraluminal filament occlusion of right middle cerebral artery (MCAO) in mice for one hour. By placing an ice box under their skull, hypothermia of mice brain was initiated immediately following MCAO for 2 h. Temporal muscle temperature was recorded and maintained between 32 and 34 °C. Brain tissue loss was assessed by hematoxylin and eosin (H&E) staining 28 days after MCAO. Quantitative real-time polymerase chain reaction (qPCR) and immunostaining were used to assess phenotype of microglia in different ischemic perfusion time. Results Hypothermia reduced brain tissue loss 28 days after ischemic stroke. Hypothermia also reduced the number of CD16-positive M1 microglia and increased the numbers of CD206-positive M2 microglia following ischemic stroke. Moreover, hypothermia also led to the reduction of the M1 markers at the level of transcription, while it increased the expression of mRNA for M2 markers. Conclusions Hypothermia is protective following ischemic stroke and can reduce brain tissue loss. Moreover, hypothermia shifts the polarization of microglia from the M1 to the M2 phenotype in the ischemic mice brain. This observed biological phenomenon may partially explain the protective effects seen due to hypothermia in acute ischemic stroke. [ABSTRACT FROM AUTHOR]

A lateral-flow immunochromatographic assay (ICA) strip was developed for determination of tenuazonic acid (TeA) using both semi-quantitative and quantitative methods. The ICA strip was based on produced anti-TeA monoclonal antibody, and could be used for TeA analysis in cereal and fruit juice, with visual limits of detection of 1600 ng/g and 400 ng/mL, and cut-off values of 6400 ng/g and 3200 ng/mL, respectively. The calculated limits of detection values were 126.4 ng/g and 65.3 ng/mL for wheat and apple juice samples, respectively. The recovery rates ranged from 90% to 129%. In summary, the developed strip was effective for TeA detection and would be suitable for on-site detection and rapid screening of samples. [ABSTRACT FROM PUBLISHER]

An immunochromatographic lateral flow strip test was developed for the detection of natamycin (Nata) residues in milk and cheese samples. Monoclonal antibody (mAb) against Nata was produced with a half maximal inhibitory concentration of 1.85 μg L−1. MAb conjugated with gold nanoparticles was the detection reagent. Nata conjugated with ovalbumin via the 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide method immobilized on a nitrocellulose membrane was the capture reagent. This semi-quantitative method required only 15 min to complete. The optimum concentrations of coating antigen and mAb were 0.15 µg mL−1and 0.2 µg mL−1, respectively. Based on an optical density scanner, the visual limit of detection of Nata was 5 μg L−1and 10 μg kg−1in milk and yoghurt samples, respectively. [ABSTRACT FROM PUBLISHER]

Three heterogenous haptens (3,4,5-Trimethoxybenzoic acid [H1], 3,4,5-Trimethoxyphenylacetic acid [H2], 3-(3,4,5-Trimethoxyphenyl) propanoic acid [H3]) were used to synthesize immunogens, with the aim of screening a more sensitive monoclonal antibody (mAb) for trimethoprim (TMP). H2 proved to be the best heterogenous hapten. The mAb was specific with no cross-reactivity with other structurally related chemicals. The 50% maximal inhibitory concentration of the mAb against TMP was 1.98 µg L−1, which is more sensitive compared with the mAb reported in our previous work. A mAb-based gold immunochromatographic assay (GICA) was established to analyze TMP residues in milk and honey samples. The concentration of coating antigen in test line and concentration of mAb conjugated with gold nanoparticles was 0.3 µg mL−1and 0.25 µg mL−1, respectively. Under optimized conditions, the visual limit of detection concentration of TMP spiked in milk and honey samples was 10 µg L−1and 15 µg kg−1, respectively. The proposed GICA provides rapid and simple determination of TMP residues in milk and honey samples. [ABSTRACT FROM PUBLISHER]