Glutaraldehyde fixation of the primary antibody-antigen complex on nitrocellulose paper increases the overall sensitivity of immunoblot assay.

A simple method to increase the overall sensitivity of immunoblot assays is described. The method is based on fixation of the primary monoclonal antibody-antigen complex on nitrocellulose paper by a divalent crosslinker, glutaraldehyde. The fixation of the antibody-antigen complex significantly increases the sensitivity of the assay. Unexpectedly, the glutaraldehyde treatment also improves the signal/noise ratio by decreasing non-specific binding of secondary antibodies and/or tertiary reagents. Thus, a significant overall improvement of immunoblot assays is achieved by this method.