An assessment of histone-modification antibody quality

Antibodies are a primary tool to assess histone post-translational modifications. However, different antibodies and batches might vary in their ability to recognize those modifications, depending on the kind of assay used. Now a systematic analysis of different antibodies and an open database containing the validation results are presented. We have tested the specificity and utility of more than 200 antibodies raised against 57 different histone modifications in Drosophila melanogaster , Caenorhabditis elegans and human cells. Although most antibodies performed well, more than 25% failed specificity tests by dot blot or western blot. Among specific antibodies, more than 20% failed in chromatin immunoprecipitation experiments. We advise rigorous testing of histone-modification antibodies before use, and we provide a website for posting new test results ( http://compbio.med.harvard.edu/antibodies/ ).