- Species-Specific Antibodies: Antibodies raised against antigens from one species may cross-react with similar antigens in another species. - Isoforms and Homologs: Different isoforms or homologs of a protein can share similar epitopes, leading to cross reactivity. - Post-translational Modifications: Modifications like phosphorylation or glycosylation can create new epitopes that are recognized by the same antibody. - Contaminants: Impurities in antibody preparations can also contribute to cross reactivity.
