Abstract 2164: In-licensing and knockout validation of monoclonal hybridomas to improve antibody reproducibility

Abstract

Antibodies are the most common tools in basic science and clinical research. Over the past several years there has been an ongoing discussion around antibody validation in light of poor experimental reproducibility between laboratories. This is in part due to the cross-reactivity between antibodies and off-target proteins and the variability between different antibody batches. The resulting experimental irreproducibility leads to wasted resources and compromises the advancement of science. Abcam partners with various research institutes and biotech companies to in-license hybridoma cell lines producing monoclonal antibodies. Through this in-licensing program, Abcam has taken steps to help ensure target-specificity of valuable clones. Our in-licensing program utilizes our ISO9001-accredited production method to ensure each batch performs in-line with previous batches. Where possible, all in-licensed antibodies are also tested in knockout (KO) material to confirm the specificity of the in-licensed clone and subsequent batches. Through our partnership with Horizon Discovery to test antibodies with KO cells, target genes are mutated via CRISPR-Cas9 within a haploid cell line, which results in a frameshift and a complete loss of gene expression. KO cell lines provide a true negative control for antibody validation that allows us to confirm the specificity of clones we in-license and produce. Alongside KO, we are making use of our expertise in recombinant antibodies to explore the conversion of selected in-licensed hybridomas to recombinant antibodies. A key issue with monoclonals is degradation of the clone over time, leading to inconsistent batches and irreproducible results. By sequencing and cloning the antibody, we expect to guarantee continued specificity and reproducibility; therefore, ensuring our licensors see long term impact and value generation for their innovations. Here we present KO data for several in-licensed published clones, validated in both western blot and immunocytochemistry. The antibodies have been tested in KO and wild-type cells to confirm their specificity. By providing researchers with reliable and specific antibodies that work as intended, we hope to minimize wasted resources and improve reproducibility. In addition to our KO data, we present data from the recombinant conversion of clone NAT105 to PD1 and show comparable, if not superior, performance when compared with the hybridoma. Citation Format: Sam Heaton, Sofia Koch, Jiangyan Ge, Joshua Rizzo, Michael Prater, Hanna Dreja, Bruce Hamilton, Alejandra Solache. In-licensing and knockout validation of monoclonal hybridomas to improve antibody reproducibility [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2164.