When I perform immunoassay using a commercial antigen(purchased from abcam) it works but when I use a positive serum sample it does not work. Can any one let me know how to remove these inhibitors from the serum?
Absence of detection by ELISA might come from an insufficient amount of protein. You could depleted the major serum protein before your incubation. It will concentrate low abundant proteins.
You need to improve incubation time between antigen and your first antibody.
And last, you could use another ELISA system, like luminex/xMAP. Luminex use beads that could be more sensitive for your application.
You could try this kit from sigma aldrich "ProteoPrep® 20 Plasma Immunodepletion Kit ". In one of my publication, I have tested few ones, all works well. No need to deplete 20 proteins, less is good too.
Article Depletion of one, six, twelve or twenty major blood proteins...