OmniDetect: a plant-produced universal IgG binder replacing secondary antibodies in immunoassays

Abstract High sensitivity in immunodetection technologies has long been a priority for both diagnostic kit development and routine laboratory research. We developed a recombinant fusion protein, OmniDetect-G3, as an alternative to conventional HRP-conjugated secondary antibodies, and successfully produced it in plants. OmniDetect-G3 binds to primary IgG antibodies regardless of host species, and also recognizes chicken IgY. In comparative analyses, OmniDetect-G3 exhibits 165–381% higher sensitivity than commercial secondary antibodies in western blot analysis and 30%-1145% higher sensitivity in ELISA, depending on commercial products tested. Moreover, OmniDetect-G3 showed robust performance when used with sera from vaccinated animals (porcine and bovine). The chemiluminescence signal generated by OmniDetect-G3 remained stable up to 30 minutes after reaction initiation. These findings indicate that plant-produced OmniDetect-G3 has strong potential as a universal mimetic to animal-derived HRP-conjugated secondary antibodies, offering simplified immunoassay workflows and improved detection efficiency.