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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]

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]

An immunochromatographic strip was developed for the determination of alternariol(AOH) using both semi-quantitative and quantitative methods based on a sensitive monoclonal antibody we produced. With AOH-spiked samples, the visual limit of detection for cereal and juice were 160 ng/g and 25 ng/mL, and the cut-off values were 640 ng/g and 100 ng/mL, respectively. For quantitative analysis based on a strip scan reader, the calculated limit of detection was 15.5–19.4 ng/g for cereal and 2.8–3.5 ng/mL for fruit juice. The recovery rates ranged from 116% to 125%, and 113% to 123%, respectively. Therefore, this method was effective for AOH detection and suitable for on-site detection and rapid screening of samples. [ABSTRACT FROM PUBLISHER]

A lateral flow colloidal gold (CG) immunoassay strip has been developed for detection of dexamethasone (DEX) residues in milk samples. For this purpose, an anti-DEX monoclonal antibody (McAb), based on a DEX succinic anhydride derivative hapten, was prepared and characterized. The McAb showed a high specificity to DEX, the half inhibitory concentration of the antibody was 0.095 ng/mL, its limit of detection (LOD) was 0.017 ng/mL, and its linear range of detection was 0.034–0.265 ng/mL. The developed CG immunoassay had a visual cut-off value of 0.3 ng/mL in phosphate buffered saline (PBS) and 0.5 ng/mL in milk samples. Each test requires 10 min. Analysis of DEX in milk indicated that the results of strip assay had a strong agreement with indirect competitive enzyme-linked immunosorbent assay. Therefore, the CG immunoassay is a sensitive screening method for semi-quantitative and qualitative detection of DEX residues in milk samples. [ABSTRACT FROM PUBLISHER]

An immunochromatographic strip was developed for detection of acetamiprid (AC) and cross-reactivity with thiacloprid (TC) in cucumber and apple samples. This detection system was developed based on a sensitive and specific monoclonal antibody produced in our laboratory. Under optimized conditions, the cut-off limits of the test strip for AC were found to be 1 and 0.25 ng/mL for TC in phosphate-buffered saline. Meanwhile, with simple preparation for detection cucumber and apple samples, the cut-off limits for AC were found to be 5 and 2.5 ng/mL for TC in cucumber samples. The immunochromatographic assay also revealed AC cut-off values of 30 and 15 ng/mL in apple samples. Each test can be evaluated within 5 min. The data indicate that the method is sensitive, rapid, specific, and has the advantages of simplicity; therefore, this immunochromatographic assay is a useful screening method for detection of AC and TC residues in cucumber and apple samples. [ABSTRACT FROM PUBLISHER]

A sensitive and specific anti-citrinin (anti-CIT) monoclonal antibody 1F2 was obtained following immunization and cell fusion. An indirect competitive enzyme-linked immunosorbent assay was developed with a 50% inhibitory concentration of 0.761 ng/mL and a limit of detection of 0.089 ng/mL. The recovery rates for CIT-spiked cereals (maize, wheat, and rice) ranged from 112% to 123%. A lateral-flow immunochromatographic assay was developed for both semi-quantitative and quantitative detection. With CIT-spiked cereals, the visual limit of detection was 8 ng/g and the cut-off value was 40 ng/g (semi-quantitative analysis with naked-eye detection). Using a strip scan reader, the calculated limit of detection was 1.28–1.8 ng/g for different CIT-spiked cereals. The recovery rates ranged from 110% to 127%. Therefore, both methods were effective for CIT detection and suitable for on-site detection and rapid screening of samples. [ABSTRACT FROM PUBLISHER]

Carbofuran is a highly toxic pesticide used in fruits and vegetables. In this study, we produced a specific and sensitive monoclonal antibody (mAb) which was prepared based on a hapten that was derivatized with benzofuranol against carbofuran. Following mice immunization and cell fusion, we obtained three monoclonal cell lines: 6D5, 3H2, and 3C6. The cell line 3H2 generated mAb with the highest affinity and sensitivity. The half maximal inhibitory concentration was 0.3 ng/mL, and the cross-reactivity was <1%. Based on this mAb, an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) and immunochromatographic test strip (ICS) assay were developed to detect carbofuran residues in cucumbers and apples. The working range of ic-ELISA was 0.1–1 ng/mL, and the cutoff value of ICS was 1 ng/mL. The analytical recovery of carbofuran in cucumber and apple samples ranged from 81% to 97%. Both methods represent rapid screening tools for carbofuran detection in fruits and vegetables. [ABSTRACT FROM AUTHOR]

A sensitive monoclonal antibody, 3G10, derived from a mouse immunized with an immunogen of salbutamol hapten conjugated to keyhole limpet hemocyanin was developed against β-agonists, with a view to establishing a rapid gold nanoparticle immunochromatographic strip. The antibody displayed a 50% inhibitory concentration (IC50) of 1.04 ng/mL for salbutamol and simultaneously detected nine other β-agonists (clenbuterol, cimatero, brombuterol, mabuterol, terbutaline, clenpenterol, carbuterol, mapenterol, pirbuterol) with uniform cross-reactivity. The immunochromatographic strip had cut-off values of 5 ng/mL for salbutamol and clenbuterol, 20 ng/mL for cimaterol, brombuterol and mabuterol, and 50 ng/mL for terbutaline, clenpenterol, carbuterol, mapenterol and pirbuterol. The collective advantages of the newly developed strip, such as high affinity, sensitivity and rapidity, support its utility in detecting β-agonists from actual biological samples, such as urine. [ABSTRACT FROM AUTHOR]

In this study, we developed an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) and an immunochromatographic strip assay based on a monoclonal antibody (mAb) against methylmercury (MeHg) to detect the presence of MeHg in tap water. Under optimum conditions (pH 8.0, 0.8% NaCl, and 0.1% Tween 20), the 50% half maximal inhibitory concentration (IC50) and limit of detection (LOD) were 16.64 and 2.03 ng/mL, respectively. The anti-MeHg mAb was specific to mercury with no cross-reactivity with other metal ions. The cut-off value of the immunochromatographic strip assay was 500 ng/mL for semi-quantitative detection, and the LOD was 11.3 ng/mL for quantitative detection. The average recovery rates of the ic-ELISA and immunochromatographic strip assay were 98.13% and 107.87%, respectively, in tap water. Therefore, ic-ELISA and the immunochromatographic strip assay can be used to detect MeHg in tap water. [ABSTRACT FROM AUTHOR]

An amikacin-sensitive monoclonal antibody (MAb) assay and immunochromatographic test strip were developed and applied for the detection of amikacin residues in bovine milk and chicken eggs. The immunoassay was specific to amikacin and showed no cross-reactivity with other aminoglycosides. The half maximum inhibitory concentration (IC50) of the assay was 0.65 ng/mL and the results were obtained within 90 min. Recoveries from spiked food matrices were within the range of 73.55–84.61% for bovine milk and 73.70–105.75% for whole egg. The strip test results were obtained within 10 min and showed a visual detection limit of 5.0 ng/mL for both food matrices. These results show that the MAb immunoassay and strip test developed in this study are very specific to amikacin and sufficiently sensitive for detection and routine monitoring of amikacin residues in food. [ABSTRACT FROM AUTHOR]