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Background: H7N9 avian influenza virus (AIV) including highly and low pathogenic viruses have been detected in China since 2013. H7N9 AIV has a high mortality rate after infection in humans, and most human cases have close contacted with poultry in the live poultry market. Therefore, it is necessary to develop a rapid point-of-care testing (POCT) technique for H7N9 AIV detection. Methods: The H7N9 AIV was inactivated and purified, and was used as the antigen to immunize BALB/c. Twelve H7-HA specific monoclonal antibodies (McAbs) were produced through the hybridoma technique. The McAb 10A8 was conjugated with colloid gold as detecting antibody; McAb 9B6 was dispensed on the nitrocellulose membran as the capture test line and the Goat-anti mouse IgG antibody was dispensed as control line respectively. The immunochromatographic strip was prepared. Results: The analysis of ELISA and virus neutralization test showed that the obtained McAbs specifically recognized H7 HA. Based on the prepared strip, the detection of H7 AIV was achieved within 10 min. No cross-reaction occurred between H7 AIVs and other tested viruses. The detection limit of the strip for H7 was 2.4 log10EID50/0.1 mL for chicken swab samples. Conclusion: The McAbs were specific for H7 and the immunochromatographic strip developed in this study was convenient, rapid and reliable for the detection of H7 AIV. The strip could provide an effective method for the rapid and early detection of H7 AIV. [ABSTRACT FROM AUTHOR]

We evaluated an immunochromatographic strip for the detection of avian avulavirus 1 (Newcastle disease virus, NDV) based on a high-affinity monoclonal antibody (mAb) that specifically recognizes the hemagglutinin-neuraminidase (HN) protein. The anti-HN mAb was labeled with colloidal gold as the detector. A chicken anti-NDV polyclonal antibody and staphylococcal protein A (SPA) were blotted on the nitrocellulose membrane for the test and control lines, respectively. The strip specifically recognized the NDV antigen with no cross-reactivity to other viruses that were examined. Furthermore, it specifically recognized a variety of NDV isolates, including virulent and attenuated strains. These results were confirmed using hemagglutination (HA) and RT-PCR assays. The NDV detection strip detected 104.9 EID50 viruses/0.1 mL in the NDV-infected sample, which is comparable to the classical HA test (105.2 EID50/0.1 mL). Following experimental infection, NDV was detected using the detection strip in infected tissues as early as 36 h after experimental infection and prior to development of clinical signs and appearance of gross anatomic lesions. The diagnostic sensitivity and specificity of the NDV detection strip for NDV infection were 83.3% and 100%, respectively, as confirmed by RT-PCR. [ABSTRACT FROM AUTHOR]

BACKGROUND Fumonisins are a kind of toxic and carcinogenic mycotoxin. A rapid immunochromatographic test strip has been developed for simultaneous detection of fumonisin B1, B2 and B3 ( FB1, FB2 and FB3) in maize based on colloidal gold-labelled monoclonal antibody ( McAb) against FB1 probe. RESULTS The anti- FB1 McAb ( 2E11-H3) was produced through immunisation and cell fusion, and identified as high affinity, specificity and sensitivity. The cross-reaction ratios with fumonisin B2 and B3 were accordingly 385% and 72.4%, while none with other analogues. The colloid gold-labelled anti- FB1 McAb probe was successfully prepared and used for establishing the immunochromatographic strip. The test strip showed high sensitivity and specificity, the IC50 for FB1 was 58.08 ng mL−1, LOD was 11.24 ng mL−1, calculated from standard curve. Moreover, the test strip exhibited high cross-reactivity with FB2 and FB3, and could be applied to the simultaneous detection of FBs ( FB1: FB2: FB3 = 12:4:1) in maize sample with high accuracy and precision. The average recoveries of FBs in maize ranged from 90.42% to 95.29%, and CVs were 1.25-3.77%. The results of the test strip for FBs samples showed good correlation with high-performance liquid chromatography analysis. CONCLUSION The immunochromatographic test strip could be employed in the rapid simultaneous detection of FB1, FB2 and FB3 in maize samples on-site. © 2016 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

An immunochromatographic lateral flow strip test using the competitive format was developed for the determination of chlorothalonil (CTN) residues in cucumber. The limit of detection was less than 100 ng/mL by visual assessment and was found to be 91.78 ± 0.17 ng/mL for quantitative detection using a test strip reader. The recoveries of test samples were from 89.26% to 102.02% and the coefficient of variation (%) was less than 4.75%. Parallel analysis of cucumber samples with CTN showed comparable results from the strip test and high performance liquid chromatography. The strip test requires 5–8 min to complete and provides a very useful screening method for the quantitative and qualitative detection of CTN residues in cucumber. [ABSTRACT FROM PUBLISHER]

• This assay can determine zeranol and its five family analogues in milk. • The cutoff values for zeranol and its analogues were all 10 ng/mL coincidentally. • The lower detection limits for zeranol and its analogues were all below 0.3 ng/mL. • The detection time of this assay is less than 15 min. Based on colloidal gold and broad-spectrum monoclonal antibody that binds to zeranol and its five analogues with high sensitivity, a lateral flow immunochromatographic assay (LFIA) in a competitive format was developed to specifically determine residues of zeranol, an illegal growth promoter in livestock. In this study, the assay had high sensitivity and was broad-spectrum only for zeranol and its five analogues, and the results were obtained within 10 min without needing sophisticated procedures. The cutoff values for zeranol and its five analogues were 10 ng/mL, and the IC 50 values for zeranol, β-zearalanol, zearalanone, α-zearalenol, β-zearalenol and zearalenone were 1.250, 1.800, 1.775, 1.225, 1.709 and 1.319 ng/mL, respectively. The recovery rates were ranged from 85.6 to 93.9%, with the coefficient of variations less than 12.4%. The results demonstrated that the LFIA could be used for rapid, simultaneous, semi-quantitative and quantitative detection of residues of zeranol and its five analogous in milk. [ABSTRACT FROM AUTHOR]