Dokument-ID Dokumenttyp Verfasser/Autoren Herausgeber Haupttitel Abstract Auflage Verlagsort Verlag Erscheinungsjahr Seitenzahl Schriftenreihe Titel Schriftenreihe Bandzahl ISBN Quelle der Hochschulschrift Konferenzname Quelle:Titel Quelle:Jahrgang Quelle:Heftnummer Quelle:Erste Seite Quelle:Letzte Seite URN DOI Abteilungen OPUS4-35381 Wissenschaftlicher Artikel Messerschmidt, Katrin; Heilmann, Katja Toxin-antigen conjugates as selection tools for antibody producing cells The generation of antibodies with designated specificity requires cost-intensive and time-consuming screening procedures. Here we present a new method by which hybridoma cells can be selected based on the specificity of the produced antibody by the use of antigen-toxin-conjugates thus eliminating the need of a screening procedure. Initial experiments were done with methotrexate as low molecular weight toxin and fluorescein as model antigen. Methotrexate and a methotrexate-fluorescein conjugate were characterized regarding their toxicity. Afterwards the effect of the fluorescein-specific antibody B13-DE1 on the toxicity of the methotrexate-fluorescein conjugate was determined. Finally, first results showed that hybridoma cells that produce fluorescein specific antibodies are able to grow in the presence of fluorescein-toxin-conjugates. Amsterdam Elsevier 2013 6 Journal of immunological methods 387 1-2 167 172 10.1016/j.jim.2012.10.010 Institut für Biochemie und Biologie OPUS4-35028 Konferenzveröffentlichung Messerschmidt, Katrin; Neumann-Schaal, Meina; Heilmann, Katja Use of antibody gene library for the isolation of specific single chain antibodies by ampicillinantigen conjugates Bethesda American Assoc. of Immunologists 2013 1 The journal of immunology 190 Institut für Biochemie und Biologie OPUS4-35158 Wissenschaftlicher Artikel Neumann-Schaal, Meina; Messerschmidt, Katrin; Grenz, Nicole; Heilmann, Katja Use of antibody gene library for the isolation of specific single chain antibodies. by ampicillin-antigen conjugates Isolation of recombinant antibodies from antibody libraries is commonly performed by different molecular display formats including phage display and ribosome display or different cell-surface display formats. We describe a new method which allows the selection of Escherichia coil cells producing the required single chain antibody by cultivation in presence of ampicillin conjugated to the antigen of interest. The method utilizes the neutralization of the conjugate by the produced single chain antibody which is secreted to the periplasm. Therefore, a new expression system based on the pET26b vector was designed and a library was constructed. The method was successfully established first for the selection of E. coli BL21 Star (DE3) cells expressing a model single chain antibody (anti-fluorescein) by a simple selection assay on LB-agar plates. Using this selection assay, we could identify a new single chain antibody binding biotin by growing E. coil BL21 Star (DE3) containing the library in presence of a biotin-ampicillin conjugate. In contrast to methods as molecular or cell surface display our selection system applies the soluble single chain antibody molecule and thereby avoids undesired effects, e.g. by the phage particle or the yeast fusion protein. By selecting directly in an expression strain, production and characterization of the selected single chain antibody is possible without any further cloning or transformation steps. Amsterdam Elsevier 2013 5 Immunology letters : an international journal providing for the rapid publication of short reports in immunology 151 1-2 39 43 10.1016/j.imlet.2013.02.005 Institut für Biochemie und Biologie