TY - GEN A1 - Herrmann, Stefan T1 - Charakterisierung zweier monoklonaler Antikörper zur Detektion von Sprengstoffen T2 - Masterarbeit N2 - In 2019 over 30 000 people were killed or injured by explosions caused by explosives like TNT, PETN, HMX and RDX. Therefore, highly sensitive assays for the detection of TNT are needed. In this study we compared two commercially available TNT antibodies: A1.1.1 and EW75C with a highly optimized indirect competitive ELISA based on a BSA-TNA conjugate. As a result, a precision profile for both antibodies was determined with a LOD of 170 pmol L-1 for the clone A1.1.1 and a LOD of 3,2 nmol L-1 for the clone EW75C. The measurements showed that the clone A1.1.1 is a highly sensitive antibody for the detection of TNT while the clone EW75C does show medium performance at most. In the cross-reactivity characterization of both antibodies many substances, closely related to the structure of TNT were tested. Both antibodies showed strong cross reactivity with trinitroaniline and trinitrobenzene. For the clone A1.1.1, which is known to originate from immunization of mice with an TNP-glycine-KLH conjugate, this has to be expected. Interestingly the clone EW75C, which was not characterized yet, showed similar behavior. This suggests a TNA-conjugate as immunogen for the EW75C antibody as well. None of both antibodies showed cross-reactions to the high explosives PETN, HMX and RDX. Also, the cross-reactions of nitro musks with the antibodies were investigated. Despite their prohibition, nitro musks are still used in Asia especially and are particularly popular in India. The overall superior clone A1.1.1 showed a significant cross-reactivity to musk ambrette. For practical reasons the influence of musk ambrette on this assay when used in natural environment should be investigated. In further experiments, the highly sensitive TNT antibody A1.1.1 was digested with papain to obtain monovalent Fab-fragments. Due to its high stability against the digestion, a custom protocol for the IgG1 subclass of mice, to which the clone A1.1.1 belongs, was developed, resulting in a quantitative digestion of the intact antibody to Fab fragments. The success of the digestion was determined with MALDI-TOF-MS and SDS-PAGE. It was shown that this protocol worked for many different antibodies of IgG1 subclass as well. KW - TNT KW - Trinitrotoluol KW - Nitroaromaten KW - Nitromoschus KW - Duftstoffe KW - ELISA KW - Immunoassay KW - Antibody KW - Explosives KW - Klon A1.1.1 KW - Klon EW75C KW - Fab Fragment KW - Kreuzreaktion KW - Crossreactivity KW - Precision Profile KW - Präzisionsprofil KW - Affinity KW - Affinitätskonstante KW - IC50 PY - 2020 SP - 1 EP - 113 PB - Hochschule für Technik und Wirtschaft Berlin - htw CY - Berlin AN - OPUS4-54556 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Tscheuschner, Georg A1 - Schwaar, Timm A1 - Weller, Michael G. T1 - Fast Confirmation of Antibody Identity by MALDI-TOF-MS Fingerprints T2 - Preprints N2 - Thousands of antibodies for diagnostic and other analytical purposes are on the market. However, it is often difficult to identify duplicates, reagent changes, and to assign the correct original publications to an antibody. This slows down scientific progress and might even be a cause of irreproducible research and a waste of resources. Recently, activities were started to suggest the sole use of recombinant antibodies in combination with the open communication of their sequence. In this case, such uncertainties should be eliminated. Unfortunately, this approach seems to be rather a long-term vision since the development and manufacturing of recombinant antibodies remain quite expensive in the foreseeable future. Also, nearly all commercial antibody suppliers may be reluctant to publish the sequence of their antibodies, since they fear counterfeiting. De-novo sequencing of antibodies is also not feasible today for a reagent user without access to the hybridoma clone. Nevertheless, it seems to be crucial for any scientist to have the opportunity to identify an antibody undoubtedly to guarantee the traceability of any research activity using antibodies from a third party as a tool. For this purpose, we developed a method for the identification of antibodies based on a MALDI-TOF-MS fingerprint. To circumvent lengthy denaturation, reduction, alkylation, and enzymatic digestion steps, the fragmentation was performed with a simple formic acid hydrolysis step. Eighty-nine unknown monoclonal antibodies were used for this study to examine the feasibility of this approach. Although the molecular assignment of peaks was rarely possible, antibodies could be easily recognized in a blinded test, simply from their mass-spectral fingerprint. A general protocol is given, which could be used without any optimization to generate fingerprints for a database. We want to propose that in most scientific projects relying critically on antibody reagents, such a fingerprint should be established to prove and document the identity of the used antibodies and to assign a specific reagent to a datasheet of a commercial supplier, a public database record or an antibody ID. KW - Reproducibility KW - Quality Control KW - Traceability KW - Diagnostics KW - ELISA KW - Immunoassay PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-506590 DO - https://doi.org/10.20944/preprints202002.0207.v1 SN - 2310-287X SP - 1 EP - 17 PB - MDPI CY - Basel AN - OPUS4-50659 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Schroeder, Barbara A1 - Le Xuan, Hoa A1 - Völzke, Jule L. A1 - Weller, Michael G. T1 - Preactivation crosslinking – An efficient method for the oriented immobilization of antibodies T2 - Preprints N2 - Crosslinking of proteins for their irreversible immobilization on surfaces is a proven and popular method. However, many protocols lead to random orientation and the formation of undefined or even inactive by-products. Most concepts to obtain a more targeted conjugation or immobilization requires the recombinant modification of at least one binding partner, which is often impractical or prohibitively expensive. Here a novel method is presented, which is based on the chemical preactivation of Protein A or G with selected conventional crosslinkers. In a second step, the antibody is added, which is subsequently crosslinked in the Fc part. This leads to an oriented and covalent immobilization of the immunoglobulin with a very high yield. Protocols for Protein A and Protein G with murine and human IgG are presented. This method may be useful for the preparation of columns for affinity chromatography, immunoprecipitation, antibodies conjugated to magnetic particles, permanent and oriented immobilization of antibodies in biosensor systems, microarrays, microtitration plates or any other system, where the loss of antibodies needs to be avoided, and maximum binding capacity is desired. This method is directly applicable even to antibodies in crude cell culture supernatants, raw sera or protein-stabilized antibody preparations without any purification nor enrichment of the IgG. This new method delivered much higher signals as a traditional method and, hence, seems to be preferable in many applications. KW - Antibody coating KW - Proximity-enhanced reaction KW - Immunoglobulins KW - IgG KW - Protein G KW - Protein A KW - Immunoprecipitation KW - Immunocapture KW - Stabilization KW - Biosensor KW - Biochip KW - Microarray KW - ELISA KW - Immunoassay KW - Immunosensor KW - Crosslinker KW - Nanoparticles KW - Click chemistry KW - Herceptin KW - Trastuzumab PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-478797 DO - https://doi.org/10.20944/preprints201904.0205.v1 SP - 1 EP - 17 PB - MDPI CY - Basel AN - OPUS4-47879 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -