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Suzhen Yang,
Jifei Yang,
Gaiping Zhang, Xuannian Wang,
Songlin Qiao,
Dong Zhao,
Yubao Zhi,
Xuewu Li,
Guangxu Xing,
Jun Luo,
Jianming Fan,
Dengke Bao
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ABSTRACT: An immunochromatographic strip was developed for the serological detection of type O foot-and-mouth disease (FMD) in swine. In the strip, the expressed protein of VP1, the main protective antigen of FMDV, labeled with colloidal gold was used as the detector, the staphylococcal protein A (SPA) and swine anti-foot-and-mouth disease virus (FMDV) antibody were blotted on the nitrocellulose membrane for the test and control lines, respectively. 296 swine serum samples were collected to evaluate the characteristics of the strip in comparison with existing commercial liquid-phage blocking ELISA (LPB ELISA) kit and peptide ELISA kit. The strip was shown to be of high specificity and sensitivity. Furthermore, the dipstick assay based on the strip is rapid (5 min) and easy to perform with no requirement of professional skills, reagents nor equipment. This suggests that the immunochromatographic strip is an acceptable alternative for use in clinical laboratories lacking specialized equipment and for field diagnosis.
Journal of virological methods 05/2010; 165(2):139-44. · 2.13 Impact Factor
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Suzhen Yang,
Jifei Yang,
Gaiping Zhang,
Songlin Qiao, Xuannian Wang,
Dong Zhao,
Xuewu Li,
Ruiguang Deng,
Aimin Zhi,
Leiming You,
Sujun Chai,
Man Teng
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ABSTRACT: An immunochromatographic strip for discriminating Foot-and-mouth disease virus (FMDV) infected from vaccinated pigs was developed based on synthetic peptide. Five peptides designed from the amino acid sequences of nonstructural proteins (NSP) of FMDV were synthesized, and pep5 located in NSP 3B reacted strongly with serum from FMDV-infected pigs but did not react with serum samples from healthy vaccinated pigs. An immunochromatographic strip was developed by using colloidal gold labeled with pep5 as the detector. Staphylococcal protein A and rabbit against peptide-conjugated ovalbumin antibody immunoglobulin G were blotted on the nitrocellulose membrane for the test and control lines. In comparison with 2 commercial NSP enzyme-linked immunosorbent assays, the peptide-based strip showed good specificity and sensitivity. The apparent agreements of this new assay with Ceditest(R) ELISA and UBI(R) ELISA were 98.59% and 96.63%, respectively. These results indicate that the strip can be adequately used to discriminate FMDV-infected animals from vaccinated animals.
Journal of veterinary diagnostic investigation: official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc 05/2010; 22(3):412-5. · 1.21 Impact Factor
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Xuewu Li,
Gaiping Zhang,
Qingtang Liu,
Chunhua Feng, Xuannian Wang,
Yanyan Yang,
Zhijun Xiao,
Jifei Yang,
Guangxu Xing,
Dong Zhao,
Shujun Cai,
Huanchun Chen
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ABSTRACT: The use of sulfonamides, such as sulfamethazine (SM2), in pig production is recognized as a public health risk as it inevitably results in sulfamethazine residues in pork. This study is aimed at establishing rapid, simple, reliable methods, with both sensitivity and specificity, for detecting sulfamethazine residues. For this purpose, monoclonal antibodies against sulfamethazine were prepared and characterized. No cross-reaction of the monoclonal antibodies was identified with other sulfonamides or analytes. Based on the competitive immunoassay principle, an indirect competitive ELISA kit (SM2 kit) and a rapid detection strip for detecting sulfamethazine residues were developed using monoclonal antibodies and the colloidal gold technique. The indirect competitive ELISA kit and the strip assay could be performed within 2 h and 5-10 min, respectively. The results showed that the detection limits were 1 ng ml(-1) for the indirect competitive ELISA kit and 8 ng ml(-1) with the unaided eye and 1 ng ml(-1) with the strip reader for the rapid strip assay. Comparing the HPLC method with the SM2-kit or the strip in pig urine spiked with standards of SM2, the difference was <4.6% for SM2-kit and 4.3% for the strip. The two methods are suitable for the rapid screening of sulfamethazine residues in swine urine. Experimental data revealed that the two methods, especially the strip, proved to be sensitive, specific, rapid and easy to use for the quantitative, semi-quantitative or qualitative detection of SM2 residues in swine urine.
Food Additives and Contaminants - Part A Chemistry, Analysis, Control, Exposure and Risk Assessment 04/2009; 26(3):314-25.
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ABSTRACT: The immunochromatographic lateral flow strip test is a one-step test that facilitates low-cost, rapid identification of various analytes at the point of care. We have developed lateral flow strip tests for the specific qualitative or semiquantitative detection of antigens, antibodies, and haptens, such as drug residues. Here, we describe in detail the preparation of three examples of the strip tests for detection of (a) the infectious bursal disease virus; (b) Trichinella specific antibodies, and (c) Clenbuterol residues in urine samples.
Methods in molecular biology (Clifton, N.J.) 02/2009; 504:169-83.
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Gaiping Zhang,
Jun Xi, Xuannian Wang,
Junqing Guo,
Hua Zhang,
Yanyan Yang,
Songlin Qiao,
Li Wang,
Hong Zhang,
Liyang He,
Yancai Zhu
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ABSTRACT: The extracellular domain of the boFcgamma2R gene was constructed and cloned into the Escherichia coli expression vector pET-28a. The recombinant protein was expressed at high level in E. coli BL21(DE3) and existed mainly as inclusion bodies. The inclusion bodies were solubilized in 6 M guanidine hydrochloride and refolded by rapid dilution. After renaturation, the purity of the recovered recombinant protein was up to 95%. ELISA assay showed that the renatured recombinant protein could inhibit bovine IgG2 binding to expressed boFcgamma2R on the COS-7 cell surface with an IC50 value of 0.68 microM. The overall yield of the active rsbo2R was up to 20 mg/l of culture. Crystals of the rsbo2R were grown at 293 K by the hanging-drop vapour diffusion method showed weak diffraction.
Journal of Immunological Methods 06/2008; 334(1-2):21-8. · 2.20 Impact Factor
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ABSTRACT: Receptors for the Fc region (FcgammaRs) of immunoglobulin G (IgG) play a crucial role in the immune system and host protection against infection. In this study, we describe the cloning, sequencing, and expression of the high-affinity IgG receptor from pig. By screening a translated Expressed Sequence Tags database with the human FcgammaRI (CD64) protein sequence, we identified a putative porcine homologue. Subsequent polymerase chain reaction amplification confirmed that the identified full-length cDNA was expressed in porcine cells. Rosetting analysis shows that COS-7 cells transfected with a plasmid containing the cloned cDNA were able to bind chicken erythrocytes sensitized with porcine IgG. Scatchard analysis indicated that monomeric IgG bound to transiently transfected cells with an affinity of approximately 4x10(7) M(-1). The porcine FcgammaRI cDNA is 1,038 nucleotides long and is predicted to encode a 346-amino-acid transmembrane glycoprotein composed of three Ig-like domains, a transmembrane region, and a short cytoplasmic tail. The overall identity of the porcine FcgammaRI to its human and mouse counterparts at the level of the amino acid sequence was 75% and 57%, respectively. Identification of porcine FcgammaRI will aid in the understanding of the molecular basis of the porcine immune system and further studies of the receptor function.
Immunogenetics 11/2006; 58(10):845-9. · 2.93 Impact Factor
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Gaiping Zhang,
Junqing Guo,
Jiyong Zhou, Xuannian Wang,
Qingmei Li,
Yanyan Yang,
Huigang Shen,
Dong Zhao,
Hua Zhang,
Jun Xi,
Li Wang,
Songlin Qiao,
Xin Jin
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ABSTRACT: To identify the linear epitope for Fc-binding on the bovine IgG2 Fc receptor (boFcgamma2R), peptides derived from the membrane-distal extracellular domain (EC1) of boFcgamma2R corresponding to the homologous region of human FcalphaRI were synthesized. Binding of bovine IgG2 to the different peptides was tested by Dot-blot assay, and the peptide showing maximal binding was further modified by truncation and mutation. The minimum effective peptide 82FIGV85 located in the putative F-G loop of the EC1 domain was found to bind bovine IgG2 specifically and inhibit the binding of bovine IgG2 to the receptor. The Phe82, Ile83 and Val85 residues within the linear epitope were shown to be critical for IgG2-binding. Such functional epitope peptide should be very useful for understanding the IgG-Fcgamma interaction and development of FcR-targeting drugs.
FEBS Letters 03/2006; 580(5):1383-90. · 3.54 Impact Factor
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Gaiping Zhang,
Jun Xi, Xuannian Wang,
Junqing Guo,
Hua Zhang,
Yanyan Yang,
Songlin Qiao,
Li Wang,
Hong Zhang,
Liyang He,
Yancai Zhu
[show abstract]
[hide abstract]
ABSTRACT: The extracellular domain of the boFcγ2R gene was constructed and cloned into the Escherichia coli expression vector pET-28a. The recombinant protein was expressed at high level in E. coli BL21(DE3) and existed mainly as inclusion bodies. The inclusion bodies were solubilized in 6 M guanidine hydrochloride and refolded by rapid dilution. After renaturation, the purity of the recovered recombinant protein was up to 95%. ELISA assay showed that the renatured recombinant protein could inhibit bovine IgG2 binding to expressed boFcγ2R on the COS-7 cell surface with an IC50 value of 0.68 μM. The overall yield of the active rsbo2R was up to 20 mg/l of culture. Crystals of the rsbo2R were grown at 293 K by the hanging-drop vapour diffusion method showed weak diffraction.
Journal of Immunological Methods.
