Knockout validation of antibodies to Ki67: a marker for cellular proliferation

TLDR: This study demonstrates the evolving strategies used in the laboratory to validate antibodies to Ki67 and hopes that by using this technique it can help to raise industry standards and contribute to the generation of reproducible research.

Abstract: At Abcam, providing a high level of validation has always been a priority and our strategies are constantly evolving as new technologies are developed. The recent knockout (KO) validation initiative, made possible through a partnership with Horizon Discovery and the use of their CRISPR/Cas9 KO cell lines, addresses both antibody specificity and reproducibility on a large scale. Ki67 is a proliferation marker and determining its expression levels has prognostic and predictive values in cancer (1–5). Hence, it is critical that antibodies used to target Ki67 are highly specific. This study demonstrates the evolving strategies used in our laboratory to validate antibodies to Ki67. The use of a human haploid cell lines where Ki67 expression has been knocked out has unequivocally identified antibodies that bind specifically to Ki67. Utilising this technology has enabled KO validation of antibodies and, at the time of abstract submission, there are over 650 KO validated antibodies on our catalogue. It is our hope that by using this technique we can help to raise industry standards and contribute to the generation of reproducible research.