Large-scale use of knockout validation to confirm antibody specificity

Antibodies are among the most common tools in basic science and clinical research. However, an increasing number of studies have shown that not all antibodies are specific, leading to a growing issue of experimental irreproducibility. This is in part due to the cross-reactivity between antibodies and off-target proteins, as well as the variability between different antibody batches. These unspecific antibodies result in wasted time and resources and compromise the advancement of science. In response to this, Abcam launched a knockout (KO) validation program in 2015 as one of its antibody quality control protocols. This initiative uses KO cells lines made possible through a partnership with Horizon Discovery. Target genes are mutated via CRISPR-Cas9 within a haploid cell line, which results in a frameshift and a complete loss of gene expression. These KO cell lines function as true negative controls that can be used at a large scale to confirm antibody specificity to the protein of interest. We have KO-validated hundreds of antibodies, including several that are relevant to immunology and immuno-oncology research. Here we present the data related to key targets validated in western blot, flow cytometry 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 first time, we hope to minimize wasted resources and improve antibody reproducibility.