The control antigen is the peptide used to immunize the animal (immunizing peptide). All polyclonal antibodies are shipped with the control antigen at no extra cost. It’s the “clear vial” you receive with the antibody.
Prior to releasing new lots of an antibody, our dedicated in-house staff performs appropriate experiments to ascertain that the new lot is as specific as the previous lot using the control antigen. Since it is highly probable that you have a different experimental setup, we provide you with the experimental tools to also determine the specificity of the antibody in your lab.
Using the control antigen is quite simple. After calibrating the conditions under which the antibody works, you can run a side by side experiment.
Incubate the antibody in parallel with and without the antigen (the ratio of antibody/antigen is available in the Certificate of Analysis delivered with the antibody) in a small volume (500 µl of 1% BSA in PBS or 3% skim milk) for 1 hour at room temperature with rotation. After the incubation time, dilute each vial to the desired working dilution with the buffer you use and apply it to the membranes for parallel experiments.
Compare the results of the antibody alone versus the antibody with the antigen. The disappearance of the requested band will confirm the specificity of the antibody.