For more information about ChIP experiment guides, troubleshooting tips and supplementary protocols, please view our Chromatin Immunoprecipitation (ChIP) page.
Antibodies
- Should I use a monoclonal or polyclonal antibody?
Either monoclonal or polyclonal antibodies can work for ChIP. Monoclonals are frequently highly specific, but monoclonals can be sensitive to crosslinking conditions. Over crosslinking may mask the target epitope and careful optimization of crosslinking might be required. Polyclonals are less sensitive to over crosslinking conditions, and may produce better enrichment than comparable monoclonals, but polyclonals are more likely to bind to nonspecific targets.
- How much antibody should I use?
We recommend using 2-10 µg of your ChIP antibody depending on the abundance of your protein target and the affinity of your antibody for the target. More antibody does not always equal stronger signal. It is suggested that to get the best ChIP signal the amount of antibody be titrated.
- How can I increase the chances of the selected antibody working in ChIP?
Test specificity/crossreactivity to identify the epitopes recognized by your antibody. You will also need to test the antibody in multiple immunoassays such as Western blot, immunocytochemistry, and immunoprecipitation, then make sure the antibody produces good fold enrichment of your target DNA in ChIP.
- How should I choose a commercial ChIP antibody?
Choose an antibody that has passed multiple specificity/crossreactivity tests, and validated in ChIP and multiple immunoassays.
- What is a good control antibody?
We recommend using normal IgG from the same species as your ChIP antibody, so if you are using a mouse monoclonal, we recommend normal mouse IgG.