The Experts below are selected from a list of 8964 Experts worldwide ranked by ideXlab platform

J. Christopher Hall - One of the best experts on this subject based on the ideXlab platform.

John C Herr - One of the best experts on this subject based on the ideXlab platform.

  • rasa a recombinant single chain Variable Fragment scfv antibody directed against the human sperm surface implications for novel contraceptives
    Human Reproduction, 2001
    Co-Authors: Elizabeth Norton, Alan B Diekman, V A Westbrook, Charles J Flickinger, John C Herr
    Abstract:

    Background: A recombinant Single-Chain Variable Fragment (scFv) antibody was engineered to a tissue-specific carbohydrate epitope located on human sperm agglutination antigen-1 (SAGA-1) a sperm glycoform of CD52. Methods and Results: cDNAs encoding the Variable regions of the S19 [IgG(-1)?] monoclonal antibody (mAb) were identified linked and cloned into the pCANTAB 5E vector. The recombinant anti-sperm antibody (RASA) was expressed in E. coli HB2151 cells as a 29 kDa monomer and remarkably also formed multimers of ~60 and 90 kDa. RASA reacted with the endogenous SAGA-1 antigen by Western blot analysis labelled the entire human sperm surface by indirect immunofluorescence and aggregated human spermatozoa in a tangled (head-to-head head-to-tail tail-to-tail) pattern of agglutination as was also observed with the native S19 mAb. Conclusions: These results demonstrate that active recombinant antibodies can be produced to a tissue-specific carbohydrate epitope on the human sperm surface thereby opening opportunities for novel contraceptive agents. (authors)

Wei Zhang - One of the best experts on this subject based on the ideXlab platform.

Christopher J Hall - One of the best experts on this subject based on the ideXlab platform.

  • increasing expression of an anti picloram single chain Variable Fragment scfv antibody and resistance to picloram in transgenic tobacco nicotiana tabacum
    Journal of Agricultural and Food Chemistry, 2005
    Co-Authors: Fernando C Oleapopelka, Michael D. Mclean, Jonathan Horsman, Kurt C. Almquist, Jim Brandle, Christopher J Hall
    Abstract:

    : Systematic research involving four chimeric gene constructions designed to express the same anti-picloram Single-Chain Variable Fragment (scFv) antibody is described. Agrobacterium-mediated transformation produced at least 25 transgenic tobacco plants with each of these, and the number of T-DNA loci in each plant was determined using kanamycin-resistance segregation assays. The relative amounts of active and total scFv in each plant were evaluated using quantitative enzyme-linked immunosorbent assay and immunoblot technologies, respectively. No significant differences in scFv activity were found among the four groups of single-locus plants, although the 35S/M construct was found to produce significantly more total anti-picloram scFv than the other three constructs. A dose-response bioassay involving T(1) seedlings from several of the highest expressers of active scFv demonstrated resistance to a constant exposure of picloram at 5 x 10(-)(8) M. Other approaches for increasing antibody-based herbicide resistance are discussed, as further improvements are needed before practical application of this technology.

Bruce D Hammock - One of the best experts on this subject based on the ideXlab platform.

  • single chain Variable Fragment antibody based immunochromatographic strip for rapid detection of fumonisin b1 in maize samples
    Food Chemistry, 2020
    Co-Authors: Wenjie Ren, Zhibing Huang, Long Zou, Shiwen Liu, Bruce D Hammock
    Abstract:

    Abstract A rapid and sensitive immunochromatographic strip (ICS) based on a Single-Chain Variable Fragment (scFv) was developed for detecting fumonisin B1 (FB1). The ICS was based on a competitive reaction for colloidal gold-labeled scFv between FB1 and FB1-BSA, which was used along with sheep anti-mouse IgG as capture reagents immobilized at test and control lines, respectively, on a nitrocellulose membrane of the strip. The limit of detection of the ICS was 2.5 ng/mL (25 μg/kg) FB1 in buffer, and the sensitivity was eight times higher than that of monoclonal antibodies for the preparation of the scFv. The cross-reactivity of the scFv with common mycotoxins was determined by ICS, the results showed that the scFv were not against other mycotoxins. Eight naturally contaminated maize samples were analyzed with the scFv-based ICS and by LC-MS/MS. The results of analysis obtained with the strip assay showed good agreement with those obtained by LC-MS/MS.

  • development of an indirect competitive enzyme linked immunosorbent assay for glycocholic acid based on chicken single chain Variable Fragment antibodies
    Analytical Chemistry, 2017
    Co-Authors: Natalia Vasylieva, Panpan Wu, Bogdan Barnych, Jun Yang, Ding Shen, Qiyi He, Suqing Zhao, Bruce D Hammock
    Abstract:

    Glycocholic acid (GCA) is an important metabolite of bile acids, whose urine levels are expected to be a specific diagnostic biomarker for hepatocellular carcinoma (HCC). A high-throughput immunoassay for determination of GCA would be of significant advantage and useful for primary diagnosis, surveillance, and early detection of HCC. Single-Chain Variable Fragment (scFv) antibodies have several desirable characteristics and are an attractive alternative to traditional antibodies for the immunoassay. Because chicken antibodies possess single heavy and light Variable functional domains, they are an ideal framework for simplified generation of recombinant antibodies for GCA detection. However, chicken scFvs have rarely been used to detect GCA. In this study, a scFv library was generated from chickens immunized with a GCA hapten coupled to bovine serum albumin (BSA), and anti-GCA scFvs were isolated by a phage-displayed method. Compared to the homologous coating antigen, use of a heterologous coating antigen ...